There is no debate as contentious as the post-Flood boundary issue within creation science. Given that testing theories is as important as developing them, this paper offers a method to test the placement of a post-Flood boundary at different points in the stratigraphic record. Marsupial fossil presence in strata below and above a suggested post-Flood boundary can be used to calculate the likelihood of those genera being found on a single continent (notably Australia or South America) both before and after the Flood. These calculations suggest that post-Flood boundary placements in the Cenozoic, within the continents noted, face a difficult challenge. Other fossil groups with high continental endemism may be similarly useful in this type of calculation. This paper’s results have implications for post-Flood biogeographic modeling.

Keywords: Post-Flood boundary, marsupials, fossil record, biostratigraphy, Australia, South America

Introduction

The placement of the Flood/post-Flood boundary in the fossil record is arguably one of the more important questions yet to reach consensus in creation science. Its placement affects how we view the geological and paleontological records, the limits and diversification of biological kinds, and the ecological and biogeographical differences between the pre- and post-Flood worlds.

Historically, creationists have suggested placement of the post-Flood boundary anywhere from the Hadean to within the Pleistocene (Holt 1996; Wise 2006). Today there are two primary camps, with late post-Flood boundary proponents typically placing the boundary within the Cenozoic, somewhere above the Oligocene-Miocene boundary (Oard 2008–2020), while early post-Flood boundary proponents place the boundary at or near the Cretaceous-Paleogene boundary (Austin et al. 1994; Whitmore and Wise 2008). Within each camp are researchers who may differ on exactly where the post-Flood boundary is placed, or even whether the boundary can be applied to exactly the same position within strata around the world (Oard 2010; Walker 2014a, 2014b; Whitmore 2006).

It can be readily determined that if the post-Flood boundary is found in later strata (for example, between the Pliocene and Pleistocene), this means that some organisms with limited biogeographical ranges (both in modern times and as seen in the fossil record) would have been living in a certain geographical region before the Flood, then upon disembarking the Ark, migrated directly back to the same region, leaving little or no trace anywhere else in the world. Take, for example, the thylacine or ‘marsupial wolf’ (Thylacinus), driven extinct in 1936 (Long et al. 2002), fossils of which can be found in Australia in Pleistocene, Pliocene, and Miocene strata (Long et al. 2002). If Miocene thylacine fossils were deposited as part of the last stage of the Flood, these animals, known only to have existed in pre-Flood Australia (however that continent was then situated), migrated to the Ark, in which they survived the Flood, then returned to post-Flood Australia. (Obviously, this scenario doesn’t imply a single pair made the entire round trip.)

This scenario is problematic (and not surprisingly, the target of skeptics [Moore 2004; Siemens 1992]). It is unlikely that the modern continent of Australia (or any other continent) was isolated as such before the Flood. Rather, all continents are believed to have been attached together as part of a much larger supercontinent (Snelling 2009). Given the vast changes in continental position due to the break-up of the pre-Flood supercontinent during the Flood, it seems unlikely that these (and other) marsupials would have specifically sought out their ancestral homeland in such a difficult-to-reach location. Invoking an innate homing beacon or divine guidance would be untestable and, in the latter case, simply God-of-the-gaps theorizing. Certainly, there is no reason to think that this geographic area would share some environmental condition both pre- and post-Flood, obligatory for marsupial survival. After all, South America has its own marsupials, and many closely related metatherian groups are found in the fossil record on other continents. (Widescale anthropogenic introductions [Woodmorappe 1990] can also be discounted as more imaginative than realistic, given the complete lack of evidence of human presence in the same strata as marsupials’ earliest appearance on either continent.)

Could it just have been the luck of the draw? At a 2018 International Conference on Creationism panel discussion, Dr. Tim Clarey, a late post-Flood boundary proponent, proposed that the probability of an organism returning to its original home region after the Flood was simply one out of the number of continents available (though he suggested five). If we follow this reasoning (and correct the number of continents to six, assuming Antarctica isn’t included), thylacines had one out of six chances to end up back in Australia. The problem with this assertion is that that probability calculation (1/6) only applies when a single species is considered. When multiple species are considered, the correct probability calculation is (1/6)x where x is the number of species considered. This means that the probability of multiple species finding their way back to the very same continent from which they started gets much smaller as more species are considered.

Marsupials are extraordinarily useful in this sort of calculation, due to their high level of continental endemism. Thus, we can place a post-Flood boundary at different positions in the stratigraphic record to calculate the probability of multiple marsupials returning to the same location in which their pre-Flood ancestors allegedly lived.

Marsupials

Marsupials are famously distinguished by their reproduction, with their young born immature and helpless. Most female marsupials have a brood pouch, or marsupium. Dental characteristics and other morphological traits also serve to distinguish marsupials from placental mammals and monotremes (Dawson et al. 1989). Living marsupials (and most fossil marsupials) are split between the superorder Australidelphia (most orders found in Australia, but also includes the South American icrobiotherians) and several orders found primarily in South America. The latter groups used to be considered part of superorder Ameridelphia, but that is now considered a paraphyletic taxon (Eldridge et al. 2019).

Marsupials are metatherians, which include a number of other marsupial-like groups now extinct (such as the South American sparassodonts, some species of which were convergently similar to sabertooth cats). Some of these have been included within the Marsupialia in the past, but are now considered distinct enough to simply be sister groups within the Metatheria. These include species from continents in North America, Asia, and Africa which have elicited comment in popular creationist literature of marsupial fossils in those regions, but which are now considered non-marsupial metatherians such as herpetotheriids, pediomyids, and peradectids (Eldridge et al. 2019; Goin et al. 2016). (Attempts to compare kangaroos to the herpetotheriids Herpetotherium of North America or Peratherium of Europe and Africa, or to the peradectid Siamoperadectes of Asia, would be like comparing distinctly different placental mammals such as cats to elephants. They do not share a relationship within the same biblical kind.)

Methodology

Two hundred and ninety-four genera of marsupials (extant and extinct) were charted and marked to show presence in any given epoch according to data within the Paleobiology Database (via the Fossilworks portal, initially examined 10/22/2018) and other published sources (see figs. 1 through 14). For the purpose of this paper, genus is used rather than species because the genus is more taxonomically stable and is more consistently recognizable in the fossil record. This conservative approach best fends off arguments that species are arbitrarily defined. Genera are sorted by family, though organization of higher taxa often varies by author (Case, Goin, and Woodburne 2005; Eldridge et al. 2019; Goin et al. 2016; Long et al. 2002); those debates are irrelevant to the purpose of this paper. We simply need to know whether a given genus is found in strata on both sides of a theorized post-Flood boundary. (Similarly, there may be some debate over whether certain genera should be classified as marsupials or nonmarsupial metatherians. Again, that is irrelevant to this calculation as the methods employed here are not dependent upon the correctness of higher-level taxonomic assignments. It may be used with any group of fossil genera, including groups of unrelated taxa.)

While it is true that the biblical kind is likely at (or above) the level of the family, this calculation would not be more effective or relevant if the family is used instead of the genus. The focus of the calculation is not on the kind, but on units within the kind which appear to be the same both before and after a proposed post-Flood boundary. If multiple genera within the same family on the same continent are found together in adjacent fossil strata (strata that are separated by a proposed post-Flood boundary), then either the genera form separate kinds (a problematic scenario) or the boundary line is incorrectly placed. If the family level is used, however, records may cover multiple genera occurring in adjacent strata without overlap (whether sister groups or ancestor-descendent pairs), which do little to inform us as to the likelihood of any alleged post-Flood boundary placement.

On the other hand, species could be used as the unit in future calculations, and would conceivably increase the number of strata-crossing records. This would simply require a rigorous determination that fossil records are correctly identified to species level. One additional objection that may be raised is that the strata on one continent may not be equivalent to another (i.e. Oligocene strata in North America may not have been created at the same time as Oligocene strata in Australia). Ross (2014a) responded to similar claims about long-distance biostratigraphic correlations, noting that they are created through “observable patterns of fossils and rocks” based on “observable, verifiable field data.” However, we can include calculations here on a ‘per continent’ basis along with an encompassing global calculation.

Results

Evaluating Late Post-Flood Boundaries

Three possible placements for a late post-Flood boundary are between (A) the Oligocene and Miocene, (B) the Miocene and Pliocene, and (C) the Pliocene and Pleistocene. Forty-six marsupial genera are found on both sides of an Oligocene-Miocene Flood boundary within a single continent. Thirty-one marsupial genera are found on both sides of a Miocene-Pliocene Flood boundary within a single continent. Sixty-one genera are found on both sides of a Pliocene-Pleistocene Flood boundary within a single continent. Didelphis (which includes the Virginia opossum) crosses both Miocene-Pliocene and Pliocene-Pleistocene boundaries, but is the only extant marsupial now native to two continents, so was not included on either list. (For the purpose of this methodology, ‘Australia’ includes Australasian islands: New Guinea, New Caledonia, and Indonesia.)

Marsupial genera crossing the Oligocene-Miocene boundary include Abderites, Balbaroo, Barguru, Bematherium, Bulungamaya, Bulungu, Burramys, Cercartetus, Clenia, Cookeroo, Dactylopsila, Djilgaringa, Ekaltadeta, Ektopodon, Eomicrobiotherium, Galadi, Galanarla, Ganawamaya, Gumardee, Ilaria, Litokoala, Madju, Marlu, Microbiotherium, Muramura, Nambaroo, Neohelos, Ngapakaldia, Nimiokoala, Onirocuscus, Palaeopotorous, Palaeothentes, Paljara, Parabderites, Perikoala, Pildra, Proargyrolagus, Propalorchestes, Pseudochirops, Silvabestius, Trelewthentes, Wabularoo, Wakaleo, Wururoo, and Yarala.

Marsupial genera crossing the Miocene-Pliocene boundary include Argyrolagus, Bettongia, Burramys, Cercartetus, Chironectes, Dactylopsila, Ektopodon, Hyperdidelphys, Hypsiprymnodon, Kolopsis, Lasiorhinus, Lutreolina, Marmosa, Microtragulus, Muramura, Onirocuscus, Paljara, Palorchestes, Perikoala, Philander, Pildra, Pliolestes, Pseudochirops, Pseudokoala, Sparassocynus, Thylacinus, Thylacoleo, Thylamys, Trichosurus, Wyulda, and Zygomaturus.

Marsupial genera crossing the Pliocene-Pleistocene boundary include Aepyprymnus, Antechinus, Baringa, Bettongia, Bohra, Burramys, Cercartetus, Chaeropus, Chironectes, Dactylopsila, Darcius, Dasycercus, Dasyuroides, Dasyurus, Dendrolagus, Dorcopsis, Euowenia, Euryzygoma, Hypsiprymnodon, Isoodon, Lasiorhinus, Lutreolina, Macropus, Marmosa, Myoictis, Nototherium, Onychogalea, Palorchestes, Perameles, Petauroides, Petaurus, Petrogale, Petropseudes, Phalanger, Phascolarctos, Phascolonus, Philander, Planigale, Potorous, Prionotemnus, Propleopus, Protemnodon, Pseudocheirus, Pseudochirops, Pseudokoala, Ramasayia, Sarcophilus, Silvaroo, Simosthenurus, Sminthopsis, Sthenurus, Thylacinus, Thylacoleo, Thylamys, Thylogale, Trichosurus, Troposodon, Vombatus, Wallabia, Wyulda, and Zygomaturus.

Using this data, we can simply calculate the probability of marsupial genera from a single pre-Flood geological region returning after the Flood to the very same location, whichever boundary placement is used. Technically, there are seven continents in the post-Flood world, and marsupial fossils have been found in Antarctica. As most early post-Flood boundary proponents agree, however, that Antarctica was covered in ice sometime within the post-Flood stage when Miocene deposits were made, Antarctica would only be relevant for earlier strata considerations. We can remove Antarctica from consideration and use (1/6)x.

For the Oligocene-Miocene boundary:

Combined probability: (1/6)46 = 1.6 × 10-36

South America only: (1/6)8 = 5.95 × 10-7

Australia only: (1/6)38 = 2.69 × 10-30

For the Miocene-Pliocene boundary:

Combined probability: (1/6)31 = 7.54 × 10-25

South America only: (1/6)9 = 9.92 × 10-8

Australia only: (1/6)22 = 7.6 × 10-18

For the Pliocene-Pleistocene boundary:

Combined probability: (1/6)61 = 3.41 × 10-48

South America only: (1/6)4 = 7.72 × 10-4

Australia only: (1/6)57 = 4.42 × 10-45

These calculations clearly show that late post-Flood boundary proponents have a serious challenge in the fossil record. The fact that these crossovers widely occur on two separate continents is evidence against complaints that it may only be an artifact of Australian Flood Geology.

To go back to our original example, is it likely that Thylacinus, along with so many other marsupials, was found in one specific geographic area before the Flood, survived on the Ark, and then made its way back to that very same region (leaving no trace elsewhere), now split off as the continent of Australia? (Or for others, South America?) It’s not only unlikely, it is highly improbable.

Evaluating Early Post-Flood Boundaries

The method in this paper provides a way to test early post-Flood boundaries as readily as late post-Flood boundaries (though we can use all seven continents). While there are numerous Cretaceous metatherians, none of these are currently accepted within the Infraclass Marsupialia (Eldridge et al. 2019). So, if the K/T boundary is postulated as recording the end of the final stage of the Flood, there is no data here that contradicts that.

Only two genera surveyed in this paper (Bardalestes and Riolestes) cross the Paleocene-Eocene boundary on a single continent, both in South America ([1/7]2 = .02). (Woodburnodon is found in South America in the Paleocene, and Antarctica in the Eocene.) Five genera cross the Eocene-Oligocene boundary on a single continent; again, all five in South America ([1/7]5 = 5.95 × 10-5).

Future studies should examine a wider range of metatherians from these periods. This will likely work better with South American metatherians. As Eldridge et al. (2019) notes, “Particularly frustrating is the near total lack of Australian fossil sites [with the exception of the Eocene Murgon fossil site] preserving mammals from the early Paleogene, as this is the period during which the Australian marsupial radiation probably began to diverge.”

Discussion

Does this calculation overexaggerate the improbability of a Cenozoic post-Flood boundary in Australia or South America? If anything, this is a conservative measure. After all, this is not a marsupial-specific argument. There are other fossil groups which would likely pair well with this calculation. Non-marsupial metatherians, monotremes, camelids, South American primates, caviomorphs, xenarthrans, and meridiungulates all show high levels of continental endemism. Any additional records showing the presence of a genus on a single continent on both sides of a postulated post-Flood boundary would serve as further evidence of low probability that such a boundary is correctly placed.

This study raises questions that may be fruitful for further research:

How many marsupials kinds are there? Creationist research on the subject is not extensive. Lightner (2012) listed hybridization reports that could be found, and generally placed the level of kind at the family (but noted that for marsupials, “it appears that it could even be above this level.”) Wise (2009) suggested there could be 1 to 5 kinds within the Australidelphia, and 6–11 within the ‘Ameridelphia.’ (Both of his groupings appear to have been calculated with what are now considered non-marsupial metatherians.) Thompson and Wood (2018) used statistical baraminology to evaluate a selection of Cenozoic mammals. Among marsupials examined, they identified the Palorchestidae, Hypsiprymnodontidae, Macropodidae, Pseudocheirinae, and Phascolarctidae as holobaramins. (Species within a holobaramin share common ancestry and share no common ancestry with other species (Wood and Murray 2003).)

Figs. 1–14 show 44 families of marsupials (along with additional unplaced genera). If the biblical kind is at the level of family, then there are, at a minimum, 44 marsupial kinds. If kinds are more inclusive (at the level of order or suborder), then there might be as few as 8 kinds. If the kind is constricted to the level of genus, then there would be 294 marsupial kinds, which is clearly untenable.

If there are only a few marsupial kinds, then it is clear that the rate and diversification of post-Flood speciation was very high. If there are more marsupial kinds, then the question as to why marsupials saturated the Australian faunal migration is raised. Either marsupials had certain characteristics that allowed them to take greater advantage of such a migration, or there was a barrier to placental mammalian migration that had little effect on marsupials. (Simpson (1940) referred to such selective passages as ‘filter-bridges,’ as opposed to open corridors or ‘sweepstakes routes’ like rafting.) For rapid diversification, creationists have a viable genetic answer within the post-Flood period (Jeanson 2017), which fits well with an early post-Flood boundary. (While Jeanson focuses on speciation within families, his application of heterozygosity as key to speciation is not inherently limited to the family level. As post-Flood populations migrated away from the Ark, speciation through shifting population sizes and inbreeding led to increased homozygosity, resulting in new genera and new species, but also a decline in the rate of speciation within each new species.)

Late post-Flood boundary proponents have a problem, however. If multiple genera within the same family are crossing the post-Flood boundary, then we have to conclude that each of those genera constitute their own biblical kind. This is because there would only be one pair of each marsupial kind on the Ark (being ‘unclean’ animals). We can see, for example, that within the family Dasyuridae (which includes quolls, marsupial mice, and the Tasmanian devil), there are eight genera found on both sides of the Pliocene/Pleistocene boundary (in fact all eight survive today). It would be absurd to argue that all eight of these genera (and a few others) were living as part of the same biblical kind before the Flood, with only one representative pair of the kind surviving on the Ark, which then returned to Australia to diversify into exactly the same genera as found before the Flood like some sort of biological memory foam. So, the late Flood-boundary proponent is stuck: either each genus is its own biblical kind (contrary to what most creation biologists would accept), or they have to discard parts of the stratigraphic record as incorrectly identified in order to fit the data to their model.

Early post-Flood boundary proponents still have questions to consider. If the marsupial fossil record is only found in post-Flood strata, does this infer that all marsupials today must have diversified from a single ancestral pair from the Ark? That seems unlikely, stretching the marsupial kind to encompass the entire infraclass. If there are multiple kinds, how did they end up only in South America/Australia?

How did marsupials reach South America? Oceanic dispersal likely played a part in the introduction of several animal groups to South America from Africa: South American tortoises, Chelonoidis, are most closely related to African hingeback tortoises, Kinixys (Le et al. 2006); the oldest New World monkey fossil, an Eocene primate from Peru, Perupithecus, resembles Eocene anthropoids in Africa (Bond et al. 2015); South American amphisbaenids (burrowing, legless reptiles) likely arrived via transatlantic dispersal on floating islands (Vidal et al. 2007); weak-flying hoatzins have fossil relatives in the African Miocene and European Eocene (Mayr, Alvarenga, and Mourer-Chauviré 2011; Mayr and de Pietri 2014), suggesting a westward transatlantic dispersion.

Founder species utilizing oceanic dispersal are usually small to medium-sized (de Queiroz 2005; Diamond 1987; Houle 1998), diversifying into larger species. (Most large marsupials do have smaller kin.) This is an area which may be quite fruitful for creation biologists and geologists; secular research has suggested that transatlantic rafting for Paleogene species may have been greatly aided by favorable winds and currents (Houle 1999). Of course, a post-Flood model would include vast amounts of floating debris rafts (Oard 2014; Wise and Croxton 2003; Wood and Murray 2003), which could be favorable to larger species in transatlantic dispersal. Ongoing secular discussion has debated whether flightless phorusrhacoid birds dispersed from Africa to South America, or vice versa (Angst et al. 2013; Mourer-Chauviré et al. 2011). Within a creation model, oceanic dispersal of this avian kind from Africa to both Europe and South America fits well with an early post-Flood boundary.

Did Antarctica have a role in post-Flood marsupial migration? The creationist literature skews towards marsupial migration to Australia via an Asian land bridge with a separate route for South American marsupials (e.g. Johnson 2012; Morris 1976; Snelling 2009; though Wood and Murray (2003) suggested independent dispersion via post-Flood rafting could explain marsupial colonization patterns), but an Antarctic connection between South America and Australia may be an alternative solution (though would have had to occur within a relatively brief period after the Flood). Several other Eocene metatherians are known from Antarctica (e.g., Derorhynchus, Xenostylus, Polydolops, Antarctodolops). There is one Paleocene-Eocene marsupial genus, Chulpasia, found in both Australia and South America, providing a direct link between those two continents. Eocene fossils referable to (or very closely related to) the Diprotodontia have been found in Patagonia (Lorente et al. 2016). Beck (2012) discussed an unnamed Eocene taxon in Australia that exhibited ‘Ameridelphian’ traits. Clues are found beyond marsupials, as well. A fossil platypus tooth found in Paleocene strata in Patagonia suggests a biogeographical connection (Pascual et al. 1992). Bourdon, de Ricqles, and Cubo (2009) noted morphological evidence for a clade comprising South American rheas and Australian emus and cassowaries, and pointed out the existence of an Eocene ratite on Seymour Island, Antarctica.

Once marsupials arrived in South America, could Antarctica have provided a bridge to Australia before freezing over? Within the secular model, Australia and New Guinea separated from Antarctica during the Eocene (approx. 40 Ma), while South America became separated from Antarctica by the opening of the Drake Passage (estimates have ranged between 17 and 49 Ma (Scher and Martin 2006)). The opening of the Drake Passage (likely aided by the opening of additional seaways around the continent (Lawver, Gahagan, and Dalziel 2011)) allowed the formation of the Antarctic Circumpolar Current which contributed to rapidly decreasing temperatures on the continent (Livermore et al. 2005). Semipermanent ice sheets began forming on the continent near the Eocene-Oligocene boundary (Ivany et al. 2006; Zachos, Breza, and Wise 1992). This secular model offers the possibility of millions of years for marsupials to travel from South America to Australia. For a creationist, however, holding to an early post-Flood boundary, there would likely only be a few hundred years available between the end of the Flood and the complete isolation of Antarctica. So is this Antarctic bridgeway plausible?

One factor that has to be considered is how quickly a species can spread over a continent in the absence of predators. The fastest known example is the rabbit, with 13 wild rabbits introduced onto a Victoria, Australia, estate in 1859. By 1866, hunters on the estate had killed 14,000 rabbits. Rabbits reached New South Wales by 1880, Queensland by 1886, and Western Australia by 1894. Over 2/3 of Australia was colonized by rabbits within fifty years of their release (National Museum of Australia n.d.). Whether early marsupials could have spread that quickly is unknown, but with regard to modern species, Gilmore (1977) noted, “certain marsupials [such as the brush-tailed possum] have proved themselves to be capable of not only holding their own, but also rapidly extending their range when introduced into a new environment.”

If the marsupial fossil record is essentially post-Flood, what can we determine from the differences between Australia and South America? Many South American marsupials (a few, such as the Didelphidae, excepted) disappeared, along with other metatherians, shortly after the Miocene, while Australian marsupials continued to thrive and diversify. One factor may have been increased competition with new species as North and South America finally connected (Marshall 1988).

What else might we learn from the biostratigraphic record? Creationists should look more closely at developing arguments that utilize the fossil record in testable ways. Ross (2012, 2014a, 2014b) and Arment (2014) demonstrate two such objective methods, using the fossil record to distinguish between pre-Flood and post-Flood strata. Brand and Chadwick (2016) noted that high percentages of paleogeographic regional endemism in mammalian families, particularly in South America and Australia, suggest that all or most Cenozoic fossils were formed after the Flood. Wise (2008, 2009, 2015) introduced a technique (the Post-Flood Continuity Criterion) which examines the size of the biblical kind and notes patterns in the fossil record (disparity of kinds and diversity within kinds) that add to our understanding of the post-Flood boundary. Wood and Cavanaugh (2003) likewise proposed ‘biological trajectories’ as one means of identifying baraminic lineages. Tomkins and Clarey (2019) attempted to use Cenozoic whale fossils to contend for a late post-Flood boundary, though nothing in their results actually rules out an earlier boundary (particularly as their mapping emphasizes coastal fossilization within a post-Flood continental landscape). There are doubtless many additional testable arguments to be raised and debated.

Table 1. Order Argyrolagoidea (Families Argyrolagidae, Groeberiidae, Patagoniidae). Data from the Paleobiology Database via Fossilworks gateway (http://fossilworks.org/) and additional material (Eldridge et al. 2019). Some researchers suggest placing the Argyrolagidae in the Polydolopimorphia or the Paucituberculata (Eldgridge et al. 2019). Chimento, Agnolin, and Novas (2015) proposed that Groeberia and Patagonia were late surviving gondwanatherians, but recent analysis retains them in the Marsupialia (Beck 2017; Eldridge et al. 2019). Zimicz and Goin (2020) noted that cladistic analysis clustered Groeberia near vombatiform diprotodontians. SA = South America. Cre Pal Eo Oli Mio Plio Plei Holo Family Argyrolagidae Anargyrolagus SA Argyrolagus SA SA Hondalagus SA Klohnia SA Microtragulus SA SA Proargyrolagus SA SA Family Groeberiidae Groeberia SA Family Patagoniidae Patagonia SA

Table 2. Order Didelphimorphia (Families Caroloameghiniidae, Sparassocynidae, Didelphidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Abello et al. 2015; Beck and Taglioretti 2019; Cozzuol et al. 2006; Eldridge et al. 2019; Marshall 1977; Solari 2005). SA = South America; NA = North America. Cre Pal Eo Oli Mio Plio Plei Holo Family Caroloameghiniidae Canchadelphys SA Caroloameghinia SA Procaroloameghinia SA Family Sparassocynidae Hesperocynus SA Sparassocynus SA SA Family Didelphidae Caluromys* SA Caluromysiops* SA Chacodelphys* SA Chironectes* SA SA SA SA Cryptonanus* SA Didelphis* SA SA SA/NA SA/NA Glironia* SA Gracilinanus* SA SA Hyladelphys* SA Hyperdidelphys SA SA Incadelphys SA Lestodelphys* SA SA Lutreolina* SA SA SA SA Marmosa* SA SA SA SA Marmosops* SA Metachirus* SA Mizquedelphys SA Monodelphis* SA SA Philander* SA SA Sairadelphys SA Szalinia SA Thylamys* SA SA SA SA Thylophorops SA Tiulordia SA Tlacuatzin* SA Zygolestes SA

Table 3. Order Paucituberculata (Families Abderitidae, Caenolestidae, Palaeothentidae, Pichipilidae, incertae sedis), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Abello 2007; Bown and Fleagle 1993; Eldridge et al. 2019; Engelman et al. 2017). SA = South America; AU = Australia. Cre Pal Eo Oli Mio Plio Plei Holo Family Abderitidae Abderites SA SA Parabderites SA SA Pitheculites SA Family Caenolestidae Caenolestes* SA Caenolestoides SA Gaimanlestes SA Lestoros* SA Perulestes SA SA Pliolestes SA SA Progarzonia SA Rhyncholestes* SA Stilotherium SA Family Palaeothentidae Acdestis SA Acdestoides SA Acdestodon SA Antawallathentes SA Carlothentes SA Chimeralestes SA Hondathentes SA Palaeothentes SA SA Pilchenia SA Propalaeothentes SA Sasawatsu SA SA Titanothentes SA Trelewthentes SA SA Family Pichipilidae Phonocdromus SA Pichipilus SA Quirogalestes SA Paucituberculata, incertae sedis Bardalestes SA SA Chulpasia SA/AU Evolestes SA Fieratherium SA Riolestes SA SA

Table 4. Order Microbiotheria (Families Microbiotheriidae, Woodburnodontidae), Order Notoryctemorphia (Family Notoryctidae), and Order Yalkaparidontia (Family Yalkaparidontidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Gelfo et al. 2019). The placement of Khasia and Mirandatherium within the Microbiotheriidae has been questioned; they may be metatherians outside the Marsupialia (Beck et al. 2008; Eldridge et al. 2019). SA = South America; ANT = Antarctica; AUS = Australia. Cre Pal Eo Oli Mio Plio Plei Holo Family Microbiotheriidae Clenia SA SA Dromiciops* SA Eomicrobiotherium SA SA SA Ideodelphys SA Khasia SA Kirutherium SA SA Marambiotherium ANT Microbiotherium SA SA SA Mirandatherium SA Oligobiotherium SA Pachybiotherium SA Pitheculus SA Family Woodburnodontidae Woodburnodon SA ANT Family Notoryctidae Naraboryctes AUS Notoryctes* AUS Family Yalkaparidontidae Yalkaparidon AUS

Table 5. Order Peramelemorphia (incertae sedis, Families Chaeropodidae, Peramelidae, Thylacomyidae, Yaralidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Gurovich et al. 2014; Kear, Aplin, and Westerman 2016; Travouillon 2016; Travouillon et al. 2014; Travouillon et al. 2015; Travouillon et al. 2017). AUS or AU = Australia; NG = New Guinea; IND = Indonesia. Cre Pal Eo Oli Mio Plio Plei Holo Peramelemorphia, incertae sedis Bulungu AUS AUS Galadi AUS AUS Kutjamarcoot AUS Lemdubuoryctes IND IND Madju AUS AUS Family Chaeropodidae Chaeropus AUS AUS AUS Family Peramelidae Crash AUS Echymipera* AU/NG Isoodon* AUS AUS AU/NG Microperoryctes* NG NG Perameles* AUS AUS AUS Peroryctes* NG Rhynchomeles* NG Silvicultor AUS Family Thylacomydiae Ischnodon AUS Liyamayi AUS Macrotis* AUS AUS Family Yaralidae Yarala AUS AUS

Table 6. Order Dasyuromorphia (incertae sedis, Families Myrmecobiidae, Malleodectidae, Thylacinidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Archer et al. 2016b; Plane 1976; Rovinsky, Evans, and Adams 2019; Wroe 2003). Eldridge et al. (2019) noted that Badjcinus has been classified as ?Thylacinidae in one recent analysis. AUS or AU = Australia; NG = New Guinea. Cre Pal Eo Oli Mio Plio Plei Holo Dasyuromorphia, incertae sedis Apoktesis AUS Dasylurinja AUS Joculusium AUS Mayigriphus AUS Mutpuracinus AUS Wakamatha AUS Family Myrmecobiidae Myrmecobius* AUS AUS Family Malleodectidae Malleodectes AUS Family Thylacinidae Badjcinus AUS Maximucinus AUS Muribacinus AUS Ngamalacinus AUS Nimbacinus AUS Thylacinus AUS AU/NG AUS AU/NG Tyarrpecinus AUS Wabulacinus

Table 7. Order Dasyuromorphia (Family Dasyuridae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Archer et al. 2016; Wroe 2003). AUS or AU = Australia; NG = New Guinea. Cre Pal Eo Oli Mio Plio Plei Holo Family Dasyuridae Antechinomys* AUS AUS Antechinus* AUS AUS AU/NG Archerium AUS Barinya AUS Dasycercus* AUS AUS AUS Dasykaluta* AUS Dasyuroides* AUS AUS AUS Dasyurus* AUS AUS AUS Ganbulanyi AUS Glaucodon AUS Micromurexia* NG Murexechinus* NG Murexia* NG Myoictis* NG NG Neophascogale* NG Ningaui* AUS AUS Paramurexia* NG Parantechinus* AUS Phascogale* AUS AUS Phascolosorex* NG Phascomurexia* NG Planigale* AUS AUS AU/NG Pseudantechinus* AUS Sarcophilus* AUS AUS AUS Sminthopsis* AUS AUS AU/NG Whollydooleya AUS

Table 8. Order Diprotodontia, Suborder Vombatiformes (Families Diprotodontidae, Ilariidae, Maradidae, Palorchestidae). Data from the Paleobiology Database via Fossilworks gateway. AUS or AU = Australia; NG = New Guinea; NC = New Caledonia. Cre Pal Eo Oli Mio Plio Plei Holo Famly Diprotodontidae Alkwertatherium AUS Bematherium AUS AUS Diprotodon AUS Euowenia AUS AUS Euryzygoma AUS AUS Hulitherium NG Kolopsis AUS NG Kolopsoides NG Maokopia NG Meniscolophus AUS Neohelos AUS AUS Nototherium NG AU/NG Plaisiodon AUS Pyramios AUS Raemeotherium AUS Silvabestius AUS AUS Sthenomerus AUS Zygomaturus AUS AU/NC AU/NG Family Ilariidae Ilaria AUS AUS Kuterintja AUS Nimbadon AUS Family Maradidae Marada AUS Family Palorchestidae Ngapakaldia AUS AUS Palorchestes AUS AUS AUS Pitikantia AUS Propalorchestes AUS AUS

Table 9. Order Diprotodontia, Suborder Vombatiformes (Families Phascolarctidae, Thylacoleonidae, Vombatidae, Wynyardiidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Black 2016; Brewer et al. 2015; Gillespie, Archer, and Hand 2017; Gillespie, Archer, and Hand 2020). AUS = Australia. Cre Pal Eo Oli Mio Plio Plei Holo Family Phascolarctidae Invictokoala AUS Koobor AUS Litokoala AUS AUS Madakoala AUS Nimiokoala AUS AUS Perikoala AUS AUS AUS Phascolarctos* AUS AUS AUS Priscakoala AUS Stelakoala AUS Family Thylacoleonidae Lekaneleo AUS AUS Microleo AUS Thylacoleo AUS AUS AUS Wakaleo AUS AUS Family Vombatidae Lasiorhinus* AUS AUS AUS AUS Nimbavombatus AUS Phascolonus AUS AUS Ramasayia AUS AUS Rhizophascolonus AUS Vombatus* AUS AUS AUS Warendja AUS Family Wynyardiidae Muramura AUS AUS AUS Namilamadeta AUS Wynyardia AUS

Table 10. Order Diprotodontia, Suborder Phalangeriformes (Families Acrobatidae, Burramyidae, Ektopodontidae, Miminipossumidae, Miralinidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Archer et al. 2018, 2019; Schwartz 2006; Rich et al. 2006). AUS = Australia; NG = New Guinea. Cre Pal Eo Oli Mio Plio Plei Holo Family Acrobatidae Acrobates* AUS AUS Distoechurus* NG Family Burramyidae Burramys* AUS AUS AUS AUS AUS Cercartetus* AUS AUS AUS AUS AUS Family Ektopodontidae Chunia AUS Darcius AUS AUS Ektopodon AUS AUS AUS Family Miminipossumidae Miminipossum AUS Family Miralinidae Barguru AUS AUS Durudawiri AUS Miralina AUS

Table 11. Order Diprotodontia, Suborder Phalangeriformes (Families Petauridae, Phalangeridae, Pilkipildridae, Pseudocheiridae, Tarsipedidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Brumm et al. 2018; Case, Meredith, and Person 2009; Crosby 2007; Leavesley 2005). AUS or AU = Australia; NG = New Guinea; IND or IN = Indonesia. Cre Pal Eo Oli Mio Plio Plei Holo Family Petauridae Dactylopsila* AUS AUS NG Gymnobelideus* AUS Petaurus* AUS AUS AU/NG Family Phalangeridae Ailurops* IND IND Eocuscus AUS Onirocuscus AUS AUS AUS Phalanger* AUS NG NG/IND Spilocuscus* AU/NG/IN Strigocuscus* AUS Trichosurus* AUS AUS AUS AUS Wyulda* AUS AUS Family Pilkipildridae Djilgaringa AUS AUS Pilkipildra AUS Family Pseudocheiridae Gawinga AUS Hemibelideus* AUS Marlu AUS AUS Paljara AUS AUS AUS Petauroides* AUS AUS AU/NG Petropseudes* AUS AUS Pildra AUS AUS AUS Pseudocheirus* AUS AUS AUS Pseudochirops* AUS AUS AUS AUS Pseudochirulus* AUS Pseudokoala* AUS AUS AUS Family Tarsipedidae Tarsipes* AUS AUS

Table 12. Order Diprotodontia, Suborder Macropodiformes (Family Macropodidae), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Flannery, Archer, and Plane 1982; Mountain 1991; Prideaux and Warburton 2009). Eldridge et al. (2019) noted that the affinities of bulungamyines (such as Bulungamaya and Cookeroo) are uncertain. AUS or AU = Australia; NG = New Guinea. Cre Pal Eo Oli Mio Plio Plei Holo Family Macropodidae Archaeosimos AUS Baringa AUS AUS Bohra AUS AUS Bulungamaya AUS AUS Congruus AUS Cookeroo AUS AUS Dendrolagus* AUS NG AU/NG Dorcopsis* AU/NG NG Dorcopsoides AUS Dorcopsulus* NG NG Ganguroo AUS Hadronomas AUS Kurrabi AUS Lagorchestes* AUS AU/NG Lagostrophus* AUS AUS Macropus* AUS AUS AU/NG Metasthenurus AUS Onychogalea* AUS AUS AUS Petrogale* AUS AUS AUS Prionotemnus AUS AUS Procoptodon AUS Protemnodon AU/NG AU/NG Rhizosthenurus AUS Setonix* AUS Silvaroo AUS AUS Simosthenurus AUS AUS Sthenurus AUS AUS Synaptodon AUS Thylogale* AUS AU/NG AU/NG Troposodon AUS AUS Wabularoo AUS AUS Wallabia* AUS AUS AUS Wanburoo AUS Watutia NG

Table 13. Order Diprotodontia, Suborder Macropodiformes (Families Balbaridae, Hypsiprymnodontidae, Potoroidae) and Order Diprotodontia (incertae sedis), asterisk indicates extant genera. Data from the Paleobiology Database via Fossilworks gateway and additional material (Arena et al. 2014; den Boer and Kear 2018; Flannery, Archer, and Plane 1982; Flannery and Rich 1986; Schwartz and Megirian 2004; Wroe 2003). Louys and Price (2015) noted that Brachalletes had been placed in both Macropodidae and Diprotodontidae, but they considered it a species inquirenda. AUS = Australia. Cre Pal Eo Oli Mio Plio Plei Holo Family Balbaridae Balbaroo AUS AUS Galanarla AUS AUS Ganawamaya AUS AUS Nambaroo AUS AUS Wururoo AUS AUS Family Hypsiprymnodontidae Ekaltadeta AUS AUS Hypsiprymnodon* AUS AUS AUS Jackmahoneyi AUS Propleopus AUS AUS Family Potoroidae Aepyprymnus* AUS AUS AUS Bettongia* AUS AUS AUS Borungaboodie AUS Caloprymnus* AUS AUS Gumardee AUS AUS Milliyowi AUS Ngamaroo AUS Palaeopotorous AUS AUS Potorous* AUS AUS AUS Purtia AUS Wakiewakie AUS Diprotodontia, incertae sedis Brachalletes AUS

Table 14. Infraclass Marsupialia (incertae sedis) and Superorder Australidelphia (incertae sedis). Data from the Paleobiology Database via Fossilworks gateway and additional material (Eldridge et al. 2019). Djarthia is recognized as Australia’s oldest fossil marsupial (Beck et al. 2008). Eldridge et al. (2019) noted that Ankotarinja and Keeuna, previously considered members of Dasyuromorphia, form a clade with Djarthia. Sigé et al. (2009) referred Thylacotinga and Chulpasia to the same sub-family, within the Polydolopimorphia, while Eldridge et al. (2019) noted that higher-level relationships are still in doubt. AUS = Australia. Cre Pal Eo Oli Mio Plio Plei Holo Marsupialia, incertae sedis Numbigilga AUS Thylacotinga AUS Yingabalanara AUS Australidelphia, incertae sedis Ankotarinja AUS Djarthia AUS Keeuna AUS

Acknowledgements

Thanks to Todd Wood for a correction on my initial calculation. Thanks to the ARJ reviewers for knowledgeable and pertinent suggestions.

References

Abello, María Alejandra. 2007. “Sistemática y Bioestratigrafia de los Paucituberculata (Mammalia, Marsupialia) del Cenozoico de América del Sur.” PhD diss. Facultad de Ciencias Naturales y Museo Universidad Nacional de La Plata.

Abello, María Alejandra, Martín de los Reyes, Adriana Magdalena Candela, Francois Pujos, Damián Voglino, and Bernardino Mamani Quispe. 2015. “Description of a New Species of Sparassocynus (Marsupialia: Didelphoidea: Sparassocynidae) from the Late Miocene of Jujuy (Argentina) and Taxonomic Review of Sparassocynus heterotopicus from the Pliocene of Bolivia.” Zootaxa 3937 no. 1 (March 24): 147–160.

Angst, Delphine, Eric Buffetaut, Christophe Lécuyer, and Romain Amiot. 2013. “‘Terror Birds’ (Phorusrhacidae) from the Eocene of Europe Imply Trans-Tethys Dispersal.” PLoS ONE 8, no. 11 (November 27): e80357. doi:10.1371/journal.pone.0080357.

Archer, Michael, Hayley Bates, Suzanne J. Hand, Trevor Evans, Linda Broome, Bronwyn McAllan, Fritz Geiser, et al. 2019. “The Burramys Project: A Conservationist’s Reach Should Exceed History’s Grasp, or What is the Fossil Record For?” Philosophical Transactions of the Royal Society B 374, no. 1788 (4 November): 20190221.

Archer, Michael, Pippa Binfield, Suzanne J. Hand, Karen H. Black, Phillip Creaser, Troy J. Myers, Anna K. Gillespie, et al. 2018. “Miminipossum notioplanetes, a Miocene Forest-Dwelling Phalangeridan (Marsupialia; Diprotodontia) from Northern and Central Australia.” Palaeontologia Electronica 21.1.2A: 1–11.

Archer, Michael, Olivia Christmas, Suzanne J. Hand, Karen H. Black, Phil Creaser, Henk Godthelp, Ian Graham, et al. 2016. “Earliest Known Record of a Hypercarnivorous Dasyurid (Marsupialia), from Newly Discovered Carbonates Beyond the Riversleigh World Heritage Area, North Queensland.” Memoirs of Museum Victoria 74 (30 July): 137–150.

Archer, M., S. J. Hand, K. H. Black, R. M. D. Beck, D. A. Arena, L. A. B. Wilson, S. Kealy, and T.-t. Hung. 2016b. “A New Family of Bizarre Durophagous Carnivorous Marsupials from Miocene Deposits in the Riversleigh World Heritage Area, Northwestern Queensland.” Scientific Reports 6: 26911 (27 May).

Arena, Derrick A., Karen H. Black, Michael Archer, Suzanne J. Hand, Henk Godthelp, and Philip Creaser. 2014. “Reconstructing a Miocene Pitfall Trap: Recognition and Interpretation of Fossiliferous Cenozoic Palaeokarst.” Sedimentary Geology 304 (1 May): 28–43.

Arment, Chad. 2014. “Fossil Snakes and the Flood Boundary in North America.” Journal of Creation 28, no. 3 (December): 13–15.

Austin, Steve A., John R. Baumgardner, D. Russell Humphreys, Andrew A. Snelling, Larry Vardiman, and Kurt P. Wise. 1994. “Catastrophic Plate Tectonics: A Global Flood Model of Earth History.” In Proceedings of the Third International Conference on Creationism. Edited by Robert E. Walsh, 609–621. Pittsburgh, Pennsylvania: Creation Science Fellowship.

Beck, Robin M. D. 2012. “An ‘Ameridelphian’ Marsupial From the Early Eocene of Australia Supports a Complex Model of Southern Hemisphere Marsupial Biogeography.” Naturwissenschaften 99, no. 2012 (5 August): 715–729.

Beck, Robin M. D. 2017. “The Skull of Epidolops ameghinoi from the Early Eocene Itaboraí Fauna, Southeastern Brazil, and the Affinities of the Extinct Marsupialiform Order Polydolopimorphia.” Journal of Mammalian Evolution 24, no. 4 (December): 373–414.

Beck, Robin M. D., and Matias L. Taglioretti. 2019. “A Nearly Complete Juvenile Skull of the Marsupial Sparassocynus derivatus from the Pliocene of Argentina, the Affinities of ‘Sparassocynids’, and the Diversification of Opossums (Marsupialia; Didelphimorphia; Didelphidae).” Journal of Mammalian Evolution, (23 July). https://link.springer.com/article/10.1007/s10914-019-09471-y.

Beck, Robin M. D., Henk Godthelp, Vera Weisbecker, Michael Archer, and Suzanne J. Hand. 2008. “Australia’s Oldest Marsupial Fossils and Their Biogeographical Implications.” PLoS One (March 26). https://doi.org/10.1371/journal.pone.0001858.

Black, Karen H. 2016. “Middle Miocene Origins for Tough-Browse Dietary Specialisations in the Koala (Marsupialia, Phascolarctidae) Evolutionary Tree: Description of a New Genus and Species from the Riversleigh World Heritage Area.” Memoirs of Museum Victoria 74 (July): 255–262.

Bond, Mariano, Marcelo F. Tejedor, Kenneth E. Campbell Jr., Laura Chornogubsky, Nelson Novo, and Francisco Goin. 2015. “Eocene Primates of South America and the African Origins of New World Monkeys.” Nature 520, no. 7548 (23 April): 538–541. doi:10.1038/nature14120.

Bourdon, Estelle, Armand de Ricqles, and Jorge Cubo. 2009. “A New Transantarctic Relationship: Morphological Evidence For a Rheidae-Dromaiidae-Casuariidae clade (Aves, Palaeognathae, Ratitae).” Zoological Journal of the Linnean Society 156, no. 3 (July): 641–663.

Bown, Thomas M., and John G. Fleagle. 1993. “Systematics, Biostratigraphy, and Dental Evolution of the Palaeothentidae, Later Oligocene to Early-Middle Miocene (Deseadan-Santacrucian) Caenolestoid Marsupials of South America.” Journal of Paleontology 29, no. 2 (March): 1–76.

Brand, Leonard, and Arthur Chadwick. 2016. Faith, Reason, and Earth History. 3rd edition. Berrien Springs, Michigan: Andrews University Press.

Brewer, Philippa, Michael Archer, Suzanne J. Hand, and Richard Abel. 2015. “New Genus of Primitive Wombat (Vombatidae, Marsupialia) from Miocene Deposits in the Riversleigh World Heritage Area (Queensland, Australia).” Palaeontologia Electronica 18.1.9a: 1–40.

Brumm, Adam, Budianto Hakim, Muhammad Ramli, Maxime Aubert, Gerrit D. van den Bergh, Bo Li, Basran Burhan, et al. 2018. “A Reassessment of the Early Archaeological Record at Leang Burung 2, a Late Pleistocene Rock-Shelter Site on the Indonesian Island of Sulawesi.” PLoS ONE 13, no. 4 (April 11): e0193025.

Case, Judd A., Francisco J. Goin, and Michael O. Woodburne. 2005. “‘South American’ Marsupials From the Late Cretaceous of North America and the Origin of Marsupial Cohorts.” Journal of Mammalian Evolution 12, nos. 3/4 (December): 461–494.

Case, Judd A., Robert W. Meredith, and Jeff Person. 2009. “A Pre-Neogene Phalangerid Possum from South Australia.” In Papers on Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne. Edited by L. Barry Albright III, 659–675. Museum of Northern Arizona Bulletin, 65.

Chimento, Nicolás R., Federico L. Agnolin, and Fernando E. Novas. 2015. “The Bizarre ‘Metatherians’ Groeberia and Patagonia, Late Surviving Members of Gondwanatherian Mammals.” Historical Biology 27, no. 5 (22 April). DOI: 10.1080/08912963.2014.903945.

Cozzuol, Mario A., Francisco Goin, Martín de los Reyes, and Alceu Ranzi. 2006. “The Oldest Species of Didelphis (Mammalia, Marsupialia, Didelphidae), From the Late Miocene of Amazonia.” Journal of Mammalogy 87, no. 4 (1 August): 663–667.

Crosby, Kirsten. 2007. “Rediagnosis of the Fossil Species Assigned to Strigocuscus (Marsupialia, Phalangeridae), with Description of a New Genus and Three New Species.” Alcheringa: An Australasian Journal of Palaeontology 31, no. 1 (5 April): 33–58.

Dawson, T. J., E. Finch, L. Freedman, I. D. Hume, Marilyn B. Renfree, and P. D. Temple-Smith. 1989. “Morphology and Physiology of the Metatheria.” In Fauna of Australia: Volume 1B Mammalia, Chaper 17. Edited by D. W. Walton and B. J. Richardson. Canberra, Australia: Australia Government Publishing Service.

den Boer, Wendy, and Benjamin P. Kear. 2018. “Is the Fossil Rat-Kangaroo Palaeopotorous priscus the Most Basally Branching Stem Macropodiform?” Journal of Vertebrate Paleontology 38, no. 2 (1 March). https://doi.org/10.1080/02724634.2017.1428196.

de Queiroz, Alan. 2005. “The Resurrection of Oceanic Dispersal in Historical Biogeography.” Trends in Ecology and Evolution 20, no. 2 (February): 68–73.

Diamond, Jared M. 1987. “How Do Flightless Mammals Colonize Oceanic Islands?” Nature 327, no. 6121 (June 4): 374.

Eldridge, Mark D. B., Robin M. D. Beck, Darin A. Croft, Kenny J. Travouillon, and Barry J. Fox. 2019. “An Emerging Consensus in the Evolution, Phylogeny, and Systematics of Marsupials and Their Fossil Relatives (Metatheria).” Journal of Mammalogy 100, no. 3 (23 May): 802–837.

Engelman, Russell K., Federico Anaya, and Darin A. Croft. 2017. “New Palaeothentid Marsupials (Paucituberculata) From the Middle Miocene of Quebrada Honda, Bolivia, and Their Implications for the Palaeoecology, Decline, and Extinction of the Palaeothentoidea.” Journal of Systematic Palaeontology 15, no. 10 (November): 787–820.

Flannery, Tim, and Thomas H. V. Rich. 1986. “Macropodoids From the Middle Miocene Namba Formation, South Australia, and the Homology of the Dental Structures in Kangaroos.” Journal of Paleontology 60, no. 2 (March): 418–447.

Flannery, T. F., M. Archer, and M. Plane. 1982. “Middle Miocene Kangaroos (Macropodoidea: Marsupialia) From Three Localities in Northern Australia, with a Description of Two New Subfamilies.” BMR Journal of Australian Geology and Geophysics 7, no. 4 (December): 287–302.

Gelfo, Javier N., Francisco J. Goin, Nicolás Bauzá, and Marcelo Reguero. 2019. “The Fossil Record of Antarctic Land Mammals: Commented Review and Hypotheses For Future Research.” Advances in Polar Science 30, no. 3 (September): 274–292.

Gillespie, Anna K., Michael Archer, and Suzanne J. Hand. 2017. “A New Oligo-Miocene Marsupial Lion From Australia and Revision of the Family Thylacoleonidae.” Journal of Systematic Palaeontology 17, no. 1 (6 December): 59–89. https://doi.org/10.1080/14772019.2017.1391885.

Gillespie, Anna K., Michael Archer, and Suzanne J. Hand. 2020. “Lekaneleo, a New Genus of Marsupial Lion (Marsupialia, Thylacoleonidae) From the Oligocene-Miocene of Australia, and the Craniodental Morphology of L. roskyellae, Comb. Nov.” Journal of Vertebrate Paleontology (February 19): e1703722. https://doi.org/10.1080/02724634.2019.1703722.

Gilmore, D. P. 1977. “The Success of Marsupials as Introduced Species.” In The Biology of Marsupials. Edited by Bernard Stonehouse, and Desmond Gilmore, 169–178. London, United Kingdom: MacMillan Press.

Goin, Francisco J., Michael O. Woodburne, Ana Natalia Zimicz, Gabriel M. Martin, and Laura Chornogubsky. 2016. A Brief History of South American Metatherians: Evolutionary Contexts and Intercontinental Dispersals. Dordrecht, Netherlands: Springer.

Gurovich, Yamila, Kenny J. Travouillon, Robin M. D. Beck, Jeanette Muirhead, and Michael Archer. 2014. “Biogeographical Implications of a New Mouse-Sized Fossil Bandicoot (Marsupialia: Peramelemorphia) Occupying a Dasyurid-Like Ecological Niche Across Australia.” Journal of Systematic Palaeontology 12, no. 3 (22 May): 265–290.

Holt, Roy D. 1996. “Evidence For a Late Cainozoic Flood/Post-Flood Boundary.” CEN Technical Journal 10, no. 1 (April): 128–167.

Houle, Alain. 1998. “Floating Islands: A Mode of Long-Distance Dispersal for Small and Medium-Sized Terrestrial Vertebrates.” Diversity and Distributions 4, no. 5/6 (September–November): 201–216.

Houle, Alain. 1999. “The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model.” American Journal of Physical Anthropology 109, no. 4 (August): 541–559.

Ivany, Linda C., Stefaan Van Simaeys, Eugene W. Domack, and Scott D. Samson. 2006. “Evidence For an Earliest Oligocene Ice Sheet on the Antarctic Peninsula.” Geology 34, no. 5 (May): 377–380.

Jeanson, Nathaniel T. 2017. Replacing Darwin: The New Origin of Species. Green Forest, Arkansas: Master Books.

Johnson, Bill. 2012. “Biogeography: A Creationist Perspective.” Creation Research Society Quarterly 48, no. 3 (Winter): 212–223.

Kear, Benjamin P., Ken P. Aplin, and Michael Westerman. 2016. “Bandicoot Fossils and DNA Elucidate Lineage Antiquity Amongst Xeric-Adapted Australasian Marsupials.” Scientific Reports 6 (24 November): 37537.

Lawver, Lawrence A., Lisa M. Gahagan, and Ian W. D. Dalziel. 2011. “A Different Look at Gateways: Drake Passage and Australia/Antarctica.” In Tectonic, Climatic, and Cryospheric Evolution of the Antarctic Peninsula. Edited by John B. Anderson and Julia S. Wellner, 5–33. Special Publication 63. Washington, D.C.: American Geophysical Union.

Le, Minh, Christopher J. Raxworthy, William P. McCord, and Lisa Mertz. 2006. “A Molecular Phylogeny of Tortoises (Testudines: Testudinidae) Based on Mitochondrial and Nuclear Genes.” Molecular Phylogenetics and Evolution 40. no. 2 (August): 517–531.

Leavesley, Matthew G. 2005. “Prehistoric Hunting Strategies in New Ireland, Papua New Guinea: The Evidence of the Cuscus (Phalanger orientalis) Remains from Buang Merabak Cave.” Asian Perspectives 44, no. 1 (March): 207–218.

Lightner, Jean K. 2012. “Mammalian Ark Kinds.” Answers Research Journal 5 (October 31): 151–204.

Livermore, Roy, Adrian Nankivell, Graeme Eagles, and Peter Morris. 2005. “Paleogene Opening of Drake Passage.” Earth and Planetary Science Letters 236, nos. 1–2 (30 July): 459–470.

Long, John, Michael Archer, Timothy Flannery, and Suzanne Hand. 2002. Prehistoric Mammals of Australia and New Guinea. Baltimore, Maryland: The Johns Hopkins University Press.

Lorente, Malena, Laura Chornogubsky, and Francisco J. Goin. 2016. “On the Existence of Non-Microbiotherian Australidelphian Marsupials (Diprotodontia) in the Eocene of Patagonia.” Palaeontology 59, no. 4 (July): 533–547.

Louys, Julien, and Gilbert J. Price. 2015. “The Chinchilla Local Fauna: An Exceptionally Rich and Well-Preserved Pliocene Vertebrate Assemblage from Fluviatile Deposits of South-Eastern Queensland, Australia.” Acta Palaeontologica Polonica 60, no. 3 (September): 551–572.

Marshall, Larry G. 1977. “First Pliocene Record of the Water Opossum, Chironectes minimus (Didelphidae, Marsupialia).” Journal of Mammalogy 58, no. 3 (20 August): 434–436.

Marshall, Larry G. 1988. “Land Mammals and the Great American Interchange.” American Scientist 76, no. 4 (July–August): 380–388.

Mayr, Gerald, and Vanesa L. de Pietri. 2014. “Earliest and First Northern Hemispheric Hoatzin Fossils Substantiate Old World Origin of a ‘Neotropic Endemic’.” Naturwissenschaften 101, no. 2 (February): 143–148.

Mayr, Gerald, Herculano Alvarenga, and Cécile Mourer-Chauviré. 2011. “Out of Africa: Fossils Shed Light on the Origin of the Hoatzin, an Iconic Neotropic Bird.” Naturwissenschaften 98, no. 11 (October): 961–966.

Moore, Greg. 2004. “Rapid Post-Flood Speciation: A Critique of the Young-Earth Model.” Evidence for God, April 29. https://godandscience.org/youngearth/speciation.html.

Morris, Henry M. 1976. The Genesis Record: A Scientific and Devotional Commentary on the Book of Beginnings. San Diego, California: Creation-Life Publishers.

Mountain, Mary-Jane. 1991. “Highland New Guinea Hunter-Gatherers: The Evidence of Nombe Rockshelter, Simbu with Emphasis on the Pleistocene.” PhD diss. Australian National University.

Mourer-Chauviré, Cécile, Rodolphe Tabuce, M’hammed Mahboubi, Mohammed Adaci, and Mustapha Bensalah. 2011. “A Phororhacoid Bird from the Eocene of Africa.” Naturwissenschaften 98, no. 10 (October): 815-823.

National Museum of Australia. n.d. “Defining Moments: Rabbits Introduced.” https://www.nma.gov.au/defining-moments/resources/rabbits-introduced.

Oard, Michael J. 2008–2020. “The Flood/Post-Flood Boundary is in the Late Cenozoic with Little Post-Flood Catastrophism.” Flood/Ice Age Research. http://michael.oards.net/PostFloodBoundary.htm

Oard, Michael J. 2010. “The Geological Column is a General Flood Order with Many Exceptions.” Journal of Creation 24, no. 2 (August): 78–82.

Oard, Michael J. 2014. “Post-Flood Log Mats Potentially Can Explain Biogeography.” Journal of Creation 28, no. 3 (December): 19–22.

Pascual, Rosendo, Michael Archer, Edgardo Ortiz Jaureguizar, José L. Prado, Henk Godthelp, and Suzanne J. Hand. 1992. “First Discovery of Monotremes in South America.” Nature 356, no. 6371 (April 23): 704–706.

Plane, M. 1976. “The Occurrence of Thylacinus in Tertiary Rocks from Papua New Guinea.” BMR Journal of Australian Geology and Geophysics 1, no. 1 (March): 78–79.

Prideaux, Gavin J., and Natalie Warburton. 2009. “Bohra nullarbora sp. nov., a Second Tree-Kangaroo (Marsupialia: Macropodidae) from the Pleistocene of the Nullarbor Plain, Western Australia.” Records of the Western Australian Museum 25, part 2: 165–179.

Rich, Thomas H., Katarzyna J. Piper, David Pickering, and Sean Wright. 2006. “Further Ektopodontidae (Phalangeroidea, Mammalia) from Southwestern Victoria.” Alcheringa: An Australasian Journal of Palaeontology 30, no. 1 (27 November): 133–140.

Ross, Marcus R. 2012. “Evaluating Potential Post-Flood Boundaries with Biostratigraphy—The Pliocene/Pleistocene Boundary.” Journal of Creation 26, no. 2 (August): 82–87.

Ross, Marcus R. 2014a. “Improving our Understanding of Creation and Its History.” Journal of Creation 28, no. 2 (August): 62–63.

Ross, Marcus R. 2014b. “Reliable Data Disconfirm a Late Cenozoic Post-Flood Boundary.” Journal of Creation 28, no. 2 (August): 66–68.

Rovinsky, Douglass S., Alistair R. Evans, and Justin W. Adams. 2019. “The Pre-Pleistocene Fossil Thylacinids (Dasyuromorphia: Thylacinidae) and the Evolutionary Context of the Modern Thylacine.” PeerJ 7 (September 2): e7457. https://doi.org/10.7717/peerj.7457.

Scher, Howie D., and Ellen E. Martin. 2006. “Timing and Climatic Consequences of the Opening of Drake Passage.” Science 312, no. 5772 (21 April): 428–430.

Schwartz, Leah R. S. 2006. “Miralinidae (Marsupialia: Phalangeroidea) from Northern Australia, Including the Youngest Occurrence of the Family.” Alcheringa: An Australasian Journal of Palaeontology 30, no. 2 (27 November): 343–350.

Schwartz, Leah R., and Dirk Megirian. 2004. “A New Species of Nambaroo (Marsupialia: Macropodoidea) from the Miocene Camfield Beds of Northern Australia with Observations on the Phylogeny of the Balbarinae.” Journal of Vertebrate Paleontology 24, no. 3 (2 August): 668–675.

Siemens, David F., Jr. 1992. “Some Relatively Non-Technical Problems with Flood Geology.” Perspectives on Science and Christian Faith 44 (September): 169–174.

Sigé, Bernard, Michael Archer, Jean-Yves Crochet, Henk Godthelp, Suzanne Hand, and Robin Beck. 2009. “Chulpasia and Thylacotinga, Late Paleocene-Earliest Eocene Trans-Antarctic Gondwanan Bunodont Marsupials: New Data from Australia.” Geobios 42, no. 6 (November–December): 813–823.

Simpson, George Gaylord. 1940. “Mammals and Land Bridges.” Journal of the Washington Academy of Sciences 30, no. 4 (April 18): 137–163.

Snelling, Andrew A. 2009. Earth’s Catastrophic Past: Geology, Creation and the Flood. Vol. 1. Dallas, Texas: Institute for Creation Research.

Solari, Sergio. 2005. “Diversity and Distribution of Thylamys (Didelphidae) in South America, with Emphasis on Species From the Western Side of the Andes.” In Predators with Pouches: The Biology of Carnivorous Marsupials. Edited by Menna Jones, Chris Dickman, and Mike Archer, 82–101. Collingwood, Victoria: CSIRO Publishing.

Thompson, C., and Todd Charles Wood. 2018. “A Survey of Cenozoic Mammal Baramins.” In Proceedings of the Eighth International Conference on Creationism. Edited by John H. Whitmore, 217–221. Pittsburgh, Pennsylvania: Creation Science Fellowship.

Tomkins, Jeffrey P., and Tim Clarey. 2019. “Whale Fossils Confirm Post-Flood Boundary.” Acts & Facts 48, no. 12 (November 27).

Travouillon, Kenny J. 2016. “Oldest Fossil Remains of the Enigmatic Pig-Footed Bandicoot Show Rapid Herbivorous Evolution.” Royal Society Open Science 3, no. 8 (1 August): 160089.

Travouillon, Kenny J., Michael Archer, Suzanne J. Hand, and Jeanette Muirhead. 2015. “Sexually Dimorphic Bandicoots (Marsupialia: Peramelemorphia) from the Oligo-Miocene of Australia, First Cranial Ontogeny for Fossil Bandicoots and New Species Descriptions.” Journal of Mammalian Evolution 22, no. 2 (September): 141–167.

Travouillon, K. J., S. J. Hand, M. Archer, and K. H. Black. 2014. “Earliest Modern Bandicoot and Bilby (Marsupialia, Peramelidae, and Thylacomyidae) from the Miocene of the Riversleigh World Heritage Area, Northwestern Queensland, Australia.” Journal of Vertebrate Paleontology 34, no. 2 (4 March): 375–382.

Travouillon, Kenny J., Julien Louys, Gilbert J. Price, Michael Archer, Suzanne J. Hand, and Jeanette Muirhead. 2017. “A Review of the Pliocene Bandicoots of Australia, and Descriptions of New Genus and Species.” Journal of Vertebrate Paleontology 37, no. 5 (29 September) e1360894.

Vidal, Nicolas, Anna Azvolinsky, Corinne Cruaud, and S. Blair Hedges. 2007. “Origin of Tropical American Burrowing Reptiles by Transatlantic Rafting.” Biology Letters 4, no. 1 (4 December): 115–118.

Walker, Tas. 2014a. “Post-Flood Boundary—A Robust Analysis Flawed by Hidden Assumptions.” Journal of Creation 28, no. 2 (August): 60–61.

Walker, Tas. 2014b. “Research Needed to Resolve Questions with Late Cenozoic Post-Flood Boundary.” Journal of Creation 28, no. 2 (August): 63–66.

Whitmore, John H. 2006. “The Geological Setting of the Green River Formation.” Journal of Creation 20, no. 1 (April): 72–78.

Whitmore, John H., and Kurt P. Wise. 2008. “Rapid and Early Post-Flood Mammalian Diversification Evidenced in the Green River Formation.” In Proceedings of the Sixth International Conference on Creationism. Edited by Andrew A. Snelling, 449–457. Pittsburgh, Pennsylvania: Creation Science Fellowship and Dallas, Texas: Institute for Creation Research.

Wise, Kurt P. 2006. “P1. Baraminology and the Flood/Post-Flood Boundary.” Plenary abstract. Occasional Papers of the BSG 8: 7–8.

Wise, Kurt P. 2008. “C11. Baraminology and the Fossil Record of the Mammals.” Contributed abstract. Occasional Papers of the BSG 11: 10–11.

Wise, Kurt P. 2009. “Mammal Kinds: How Many Were on the Ark?” In Genesis Kinds: Creationism and the Origin of Species. Edited by Todd Charles Wood and Paul A. Garner, 129–161. Center for Origins Research Issues in Creation, No. 5. Eugene, Oregon: Wipf and Stock.

Wise, Kurt P. 2015. “Paleontological Notes on the Baraminology of Frogs.” Abstract. Journal of Creation Theology and Science Series B: Life Sciences 5: 7.

Wise, Kurt P., and Matthew Croxton. 2003. “Rafting: A Post-Flood Biogeographical Dispersal Mechanism.” In Proceedings of the Fifth International Conference on Creationism: Technical Symposium Sessions. Edited by Robert L. Ivey, Jr., 465–478. Pittsburgh, Pennsylvania: Creation Science Fellowship.

Wood, Todd Charles, and David P. Cavanaugh. 2003. “An Evaluation of Lineages and Trajectories as Baraminological Membership Criteria.” Occasional Papers of the Baraminology Study Group 2: 1–6.

Wood, Todd Charles, and Megan J. Murray. 2003. Understanding the Pattern of Life: Origins and Organization of the Species. Nashville, Tennessee: Broadman & Holman.

Woodmorappe, John. 1990. “Causes for the Biogeographic Distribution of Land Vertebrates After the Flood.” In Proceedings of the Second International Conference on Creationism. Vol. 2. Edited by Robert E. Walsh and Chris L. Brooks, 361–371. Pittsburgh, Pennsylvania: Creation Science Fellowship.

Wroe, Stephen. 2003. “Australian Marsupial Carnivores: Recent Advances in Palaeontology.” In Predators with Pouches: The Biology of Marsupial Carnivores. Edited by Menna Jones, Chris Dickman, and Mike Archer, 102–123. Collingwood, Victoria: CSIRO Publishing.

Zachos, James C., James R. Breza, and Sherwood W. Wise. 1992. “Early Oligocene Ice-Sheet Expansion on Antarctica: Stable Isotope and Sedimentological Evidence from Kerguelen Plateau, Southern Indian Ocean.” Geology 20, no. 6 (June): 569–573.

Zimicz, Ana Natalia, and Francisco Javier Goin. 2020. “A Reassessment of the Genus Groeberia Patterson, 1952 (Mammalia, Metatheria): Functional and Phylogenetic Implications.” Journal of Systematic Palaeontology. https://doi.org/10.1080/14772019.2019.1706195