Episode 414: A giant carcharodontosaur and a tiny titanosaur. Plus evidence of a large dinosaur from an island, a new juvenile T. rex specimen, connecting dinosaurs to chocolate, and much more

News:

• New “giant theropod material” may be a third carcharodontosaurid in Cretaceous Morocco or more support for the dinosaur Sauroniops source
• There’s a new titanosaur, Ibirania, which looked like other sauropods although smaller—despite not being on an island source
• A new massopodan sauropodomorph Tuebingosaurus maierfritzorum has been named from Germany source
• A new juvenile T. rex was recently fund and is on display in Colorado source
• A new study shows that many dinosaurs were endothermic (“warm blooded”), while others were ectothermic (“cold blooded”) source
• Shortly before hatching, a bird’s pelvis looks the same as a dinosaur’s pelvis source
• Not all dinosaurs that lived on islands may have been small source
• Scientists identified the first record of dinosaur tracks in what is now Palestine and published a nice set of criteria for identifying tracks source
• There’s at least 38 trackways and more than 350 dinosaur footprints at the TY tracksite in southern Africa source

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The dinosaur of the day: Zanabazar

• Troodontid that lived in the Late Cretaceous in what is now Mongolia (Nemegt Formation)
• Looked similar to Troodon
• Paleoart shows large claws, long tail, S-curved neck, and feathered
• One of the largest troodontids
• Largest known Asian troodontid
• Estimated to grow up to 7.5 ft (2.3 m) long and weigh 55 lb (25 kg)
• Skull was 10.7 in (27.2 cm) long
• Had a large brain compared to its body size
• Fossils first found in 1964 as part of the first joint Mongolian-Soviet Paleontological Expedition
• Originally named a new species, Saurornithoides junior, by Rinchen Barsbold in 1974
• Type species of Saurornithoides is Saurornithoides mongoliensis
• Reclassified in 2009 as Zanabazar junior by Mark Norell and others
• Zanabazar was the first spiritual head of Tibetan Buddhism in Outer Mongolia (lived between 1635 to 1723)
• Henry Osborn named Saurornithoides mongoliensis in 1924, based on a skull and fragments of the body
• At the time, Troodon formosus was known only from teeth and not recognized as a theropod, so Osborn compared Saurornithoides with Velociraptor, and suggested “it may prove to have avian relationships”
• Zanabazar was referred to Saurornithoides because of similarities (Saurornithoides was the only other well known troodontid with a skull), and both being from the Late Cretaceous of Central Asia
• More troodontid specimens had been described in the 1980s to early 2000s, which is why Zanabazar was re-examined
• Holotype includes a nearly complete skull and braincase, some tail vertebrae, and right hindlimb
• Holotype vertebrae are completely fused, which means it probably was an adult
• Norell and others did CT scans and found enough differences between Saurornithoides junior (Zanabazar) and Saurornithoides mongoliensis. Both were only known from their holotypes
• Norell and others acknowledged this was only based on two specimens, but both holotypes are adults
• Zanabazar is larger than Saurornithoides
• Zanabazar skull is 272 mm (10.7 in) long, and Saurornithoides skull is 189 mm (7.4 in) long
• Zanabazar has more teeth than Saurornithoides (118 compared to 108), the braincase looks slightly different, and other details
• Lots of similarities with Saurornithoides but could be because the similarities are plesiomorphic (ancestral characters) and shared with other troodontids, including Troodon formosus
• Two other troodontids have been described that were found in the Nemegt Formation: Borogovia (known from a partial hind limb) and Tochisaurus (known from some foot bones). But, Zanabazar doesn’t have those bones preserved, so can’t compare and known if some of these dinosaurs are synonymous
• Other dinosaurs that lived around the same time and place include tyrannosaurs, ankylosaurs, alvarezsaurs, dromaeosaurs, hadrosaurs, ornithomimosaurs, pachycephalosaurs, sauropods, therizinosaurs
• Other animals that lived around the same time and place include amphibians, crocodylomorphs, fish, mammals, pterosaurs, turtles

Fun Fact:

Over 200 animals and other things have been named after J.R.R. Tolkien and his works.

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