Episode 248 is all about Polacanthus, an ankylosaur that was described in the 1800s, but no one is sure who named it.

Big thanks to all our patrons! Your support means so much to us and keeps us going! If you’re a dinosaur enthusiast, join our growing community on Patreon at https://www.patreon.com/iknowdino.

You can listen to our free podcast, with all our episodes, on Apple Podcasts at: https://itunes.apple.com/us/podcast/i-know-dino/id960976813?mt=2

In this episode, we discuss:

News:

After decades of being classified as Massospondylus, “grey skull” has a new name, Ngwevu intloko source

Mission Jurassic in North Wyoming could hold over 100 dinosaurs in one square mile source

A group of juvenile hadrosaurs was found at Pipestone Creek, near the Philip J. Currie Museum source

The Scottish government is working on better protecting the fossils on the Isle of Skye in Scotland source

In India, a group of scientists are pushing for a bill that will designate and safeguard fossil sites source

In Romania, new dinosaur nests have been found, most likely from a hadrosaur like Telmatosaurus source

The Natural History Museum in London has digitized their holotype of Mantellisaurus source

The Central Museum of Mongolian Dinosaurs recently opened a new exhibition hall, themed Paleozoic Era source

Dinosaur Park in Laurel, Maryland has an open house this summer, on September 7 source

Trix the T.rex is back in Leiden, at the updated Naturalis Biodiversity Center in the Netherlands source

A new project called “On the Trail of Dinosaurs,” will bring the Dinosaur Tracks from the Australian Dampier Peninsula to life source

children visiting the North Carolina Museum of Natural Sciences regularly try to help the injured sauropod, giving it hugs and Band-Aids. source

South Dakota rancher Kenny Brown recently retired and bequeathed his 1,330 acre ranch to the School of Mines source

PLOS One blog has a list of events for National Fossil Day in the US (October 16) source

On August 29, the US Postal Service is issuing four new T. rex stamps, with a holographs source

Nickelodeon has a new animated series coming out September 14, LEGO Jurassic World: Legend of Isla Nubar source

The dinosaur of the day: Polacanthus

Ankylosaur that lived in the Early Cretaceous in what is now England (Upper Wessex Formation)

Quadrupedal ornithischian

Not well known (especially the skull)

Estimated to be about 16 ft (5 m) long

Gregory Paul estimated it to weigh 2 tonnes

Had relatively long hindlimbs

Body had armor plates and spikes

Had a large pelvic or sacral shield (bone over the hips). The holotype has four rows of larger osteoderms on the side, with smaller ossicles

John Whitaker Hulke in the late 1800s suggested the tail had two rows of osteoderms on each side

Franz Nopcsa in 1905 thought the tail and front of the body had two parallel rows of spikes, one on each side

Wiliam T Blows in 1987 mostly agreed with Nopcsa but said there were three spike types

Type species: Polacanthus foxii

Found in 1865 on the Isle of Wight by Reverend William Fox

Genus means “many thorns” or “many prickles”

The genus name refers to the spikes on its armor

The species name refers to Fox

Fox at first was going to have his friend Alfred Tennyson name the dinosaur. Tennyson suggested naming it Euacanthus vectianus but this wasn’t accepted

Fox mentioned the find in a lecture to the British Association, and let Richard Owen name it Polacanthus foxii

The Illustrated London News printed an anonymous article with Fox’s lecture but there’s no corresponding publication by Owen

Some people think that Thomas Huxley named the dinosaur, others think it was Owen, Fox, or someone anonymous

Holotype consists of an incomplete skeleton (includes vertebrae, sacrum, most of the pelvis, most of the left hindleg, ribs, chevrons, ossified tendons, and spikes)

Early illustrations gave it a generic head (only knew the back half)

John Whitaker Hulke published the first description of the dinosaur in 1881, and said it had deteriorated over the years (the armor had mostly fallen apart). But then Fox died (same year), and his fossils were acquired by the British Museum of Natural History. Caleb Barlow reassembled Polacanthus, even though Hulke thought it couldn’t be done

Hulke redescribed Polacanthus in 1887, focusing on the armor

Then in 1905, Franz Nopcsa described Polacanthus and illustrated the spikes

Other possible specimens included two found in 1843 by John Edward Lee

More have been referred, and they include parts of the armor or single bones

Wiliam T Blows exacavated a second partial skeleton (with parts of the skull) in 1979. Parts of it had been removed since 1876

Many species have been named but only one species is considered to be valid now

Other species names include Polacanthus becklesi (now considered to be a junior synonym), Polacanthus marshi (Blows claimed in 1987 that Hoplitosaurus was Polacanthus marshi, but this has now been rejected), Polacanthus rudgwickensis (named by Blows in 1996 aftering reviewing fossils found in 1985 thought to be Iguanodon, it’s about 30% longer than Polacanthus foxii but in 2015 Blows named it as a separate genus, Horshamosaurus)

Also, Polacanthus ponderosus (Nopcsa named in 1928 based on a left scapula that Gideon Mantell had thought was Hylaeosaurus, as well as a tibia and humerus from another specimen, but it turns out the tibia and humerus were found on Wight, and are casts, while the scapula was from Bolney)

Walter Coombs renamed Polacanthus foxii to Hylaeosaurus foxi in 1971, but this has not been accepted

Some people have thought Polacanthus was the same as Hylaeosaurus armatus, but Blows rejected that in 1987 based on age and anatomical differences

Fun Fact: There is new evidence that some theropods in Mongolia laid eggs in groups at nesting sites.