In our 122nd episode, we had the pleasure of speaking with Dr. Thomas Hegna, Assistant Professor at Western Illinois University, who specializes in invertebrates, specifically arthropods; and Robert Johnson, Curator of the Geology Museum at WIU, and the artist who makes awesome dinosaur 3D prints look just like authentic fossils.

Episode 122 is also about Lourinhanosaurus, a theropod that lived in the Jurassic in what is now Portugal.

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In this episode, we discuss:

News:

The dinosaur of the day: Lourinhanosaurus

Name means Lourinhã [Formation] lizard

Theropod that lived in the Jurassic in what is now Portugal

Discovered in 1982 near Lourinhã, Portugal

Described in 1998 by Octávio Mateus

Type species is Lourinhanosaurus antunesi

Species named in honor of Miguel Telles Antunes, a Portuguese paleontologist

Holotype is a partial skeleton, with vertebrae from the ribs, the right tibia and fibula, a metatarsus, and 32 associated gastroliths

Holotype was a sub-adult

About 15 ft (4.5 m) long and weighed about 350 lb (160 kg). Estimated that it would take 10 years to reach adult size, and an adult would be 26 ft or 8 m long

No real agreement on where Lourinhanosaurus belongs. At first it was thought to be part of Allosauroidea, but now some scientists think it was part of Megalosauroidea. In 2010, Benson said it was part of Sinraptoridae, and in 2012 Carrano said it was a coelurosaur

If Lourinhanosaurus is a sinraptorid, it would be the first one found outside of China

In 1993, about 100 eggs (some with embryonic bones) were found at a nearby beach, Paimogo. In 2001, they were assigned to Lourinhanosaurus

Eggs found were about 5 in (13 cm) long, and thought to be Lourinhanosaurus because they were found near the type specimen

Can see Lourinhanosaurus and the eggs at the Museu da Lourinhã

Carnivorous

First known theropod to have gastroliths, and scientists determined they weren’t swallowed accidentally when eating an herbivorous dinosaur

Gastroliths may have helped tenderize meat (carnivorous dinosaurs not great at chewing), or Lourinhanosaurus may have eaten shellfish and crustaceans and the gastroliths helped crack the shells (unclear if that’s what happened, since no skull was found)

Europe in the Jurassic had many islands, so animals may have adapted to different kinds of foods

It’s also possible that Lourinhanosaurus changed what it ate as it grew older (like how tyrannosaurs are faster and more agile and chase smaller ornithopods, and then when they get bigger and older, they go for larger dinosaurs)

As a juvenile, it’s possible Lourinhanosaurus went to beaches to eat smaller dinosaurs or eat fish and crustaceans from tidal pools (and then swallowed gastroliths to help digest them). Then as an adult, it may have started hunting larger dinosaurs for food

Fun fact: We can determine the age of dinosaurs by counting Lines of Arrested Growth (LAGs) in bones. It’s similar to counting tree rings. We infer that growth slows down just once a year from comparisons to modern animals (like crocodiles).

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For those who may prefer reading, see below for the full transcript of our interview with Dr. Thomas Hegna and Robert Johnson:

COMING SOON!