The Big Dinosaur Podcast

In our 88th episode, we got to speak with Thea Boodhoo and Dr. Bolorsetseg Minjin from the Institute for the Study of Mongolian Dinosaurs.

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Episode 88 is all about Baryonyx the smaller cousin of Spinosaurus.

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In this episode, we discuss:

• The dinosaur of the day: Baryonyx
• Name means “heavy claw”, has a large claw on its first finger
• Theropod that lived in the Cretaceous
• Type species is Baryonyx walkeri
• Species name is in honor of the fossil hunter William J. Walker, who discovered it
• Holotype found in 1983 in Surrey, England
• Named in 1986
• William Walker was a plumber, who hunted fossils in his free time
• Walker found a large claw, phalanx bone, and part of a rib in a clay pit in Surrey, England (found the tip of the claw a week later)
• Alan Charig and Angela Milner described Baryonyx in 1986
• Paleontologists found more bones, and holotype consisted of partial skull bones, teeth, vertebrae, ribs, sternum, arm and hand bones, hip and leg bones, and claws
• Other fragments have been found in other parts of the UK and Iberia
• Baryonyx teeth have been found in the UK and Iberia, as well as some hand bones and a vertebra
• In 1999 bones, a tooth, and a phalanx, metacarpals, and vertebra remains were found in Spain (an immature Baryonyx), and dinosaur tracks nearby have been found to be Baryonyx too
• Jaw fragments and teeth found in Portugal that were thought to be crocodilian were redescribed and referred to Baryonyx
• Paper: The spinosaurid dinosaur Baryonyx (Saurischia, Theropoda) in the Early Cretaceous of Portugal, published in Geological Magazine 144(06) · October 2007,
  More material found in Portugal (partial dentary, isolated teeth, vertebrae rib fragments and more) from the early Cretaceous.
• In 2011 a speciman in Portugal was attributed to Baryonyx, and it included teeth, vertebrae, ribs, hip bones, scapula, and phalanx bone
• Paper: A new specimen of the theropod dinosaur Baryonyx from the early Cretaceous of Portugal and taxonomic validity of Suchosaurus by OCTÁVIO MATEUS1,2, RICARDO ARAÚJO2,3, CARLOS NATÁRIO2 & RUI CASTANHINHA, published 2011
• Portugal specimen referred to Baryonyx because of the teeth being similar
  Baryonyx was the first early Cretaceous theropod found in the world and was in the media a lot (last significant theropod found in UK was in 1871, Eustreptospondylus).
• Was in the 1987 BBC documentary and nicknamed “Claws” (as a pun to the film Jaws
  First theropod found that showed theropods ate fish (holotype had fish scales in the stomach region)
• Before Baryonyx, scientists thought theropods and other carnivorous dinosaurs had boxy, round skulls, not narrow skulls
• Baryonyx was key to identifying the spinosaur group (before, teeth thought to be crocodiles, and the original Spinosaurus fossils were destroyed in WWII)
• Holotype is one of the most complete theropods from the UK
• Holotype may not have been a full grown adult
• When first found, it was unclear if the large claw was on the hand or foot (like dromaeosaurs), and was described eventually in more detail later (published in 1997)
• About 25 ft (7.5 m) long and weighed 1.2 tons
• First finger claw was about 12 in (31 cm) long
• A fully grown Baryonyx may have been much larger (based on its relative Spinosaurus, which was about 46 ft (14 m) long and weighed 10 tons)
• Neck was curved, but not quite as curved as other theropods
• Had strong forelimbs
• Lived near water
• Probably could swim, though probably not aquatic (nostrils were at side of the snout)
• Had a triangular crest on top of the nasal bones
• Had an elongated skull
• Had a long, low snout and narrow jaws
• The maxilla and premaxilla are simlar to Dilophosaurus
• A CT scan of snouts in 2007 found that Baryonyx was most similar to gharials, which also means they were likely to eat fish
• In 2013, a test found that Baryonyx’s snout could take more stress bending and twisting than gharials
• Scientists saw the similarities between Baryonyx and Spinosaurus (though Baryonyx did not have a sail)
• Had a notch at the end of its jaws, similar to crocodiles, which they use to help grip slippery prey like fish
• May have been a predator and a scavenger (holotype also had bones of a juvenile Iguanodon); could have caught prey with large forelimbs and claws
• Other dinosaurs in the area included Iguanodon, Mantellisaurus, and small sauropods
  In 1987 Andrew Kitchener suggested Baryonyx was a scavenger and used its claws to rip open prey and long snout to dig in to its food; jaws and teeth may have been too weak to catch fish or kill prey
• In 1997 Charig and Milner found evidence that it ate fish (saw acid-eteched scales and teeth of fish in the stomach region), as well as juvenile Iguanodon bones and a gastrolith; could have caught fish like a crocodile, by gripping with a notch in the snout, lifting their head backwards, and swallowing the fish headfirst (then used claws to break up bigger fish)
• Long snout and serrated teeth show it ate fish (could have used its claw to fish, like a grizzly bear)
• Long teeth are good for holding prey, not crunching
• Had serrated, conical teeth
• Had small, pointed teeth
• Had more teeth in the lower jaw than upper jaw (64 in lower jaw, 32 in dentary and 7 in the right premaxilla)
• Had more teeth than most theropods (almost twice as many as T-rex)
  Baryonyx teeth are similar to Suchosaurus, and some scientists think they are the same animal. Others think they’re just closely related. But since Suchosaurus is based only on teeth and jaw fragments, there’s not enough information
• Suchosaurus is possibly a synonym (named in 1841, based on teeth), teeth are probably of a spinosaurid, though slightly different from Baryonyx
• But, Baryonyx teeth vary between individuals
• Both Suchosaurus species, Suchosaurus cultridens and Suchosaurus girardi are nomina dubia, because of a lack of diagnostic apomorphies
• Can see the skeleton at the Natural History Museum in London
• Fun Fact: Megaraptor, was named a “raptor” largely because of big dromaeosaur-like claw that was found with the holotype so it was assumed to be a large toe claw like the one on velociraptor. But later a more complete specimen was found where the claw turned out to be attached to the hand. So now it’s family is much less certain. The leading groups seem to be tyrannosauroid, spinosauroid, and allosauroid, but it’s still being debated.

For those who may prefer reading, see below for the full transcript of our interview with Thea and Bolor:Continue Reading …