Episode 551: Weird & Dead Treasures. Amy Atwater, co-host of Weird & Dead joins to discuss some of her favorite fossils and her new book The Fossil Keeper’s Treasure. Plus a new ornithomimosaur with big hands, Mexidracon, and monstersaurs

News:

• There’s a new ornithomimosaur with very large hands named Mexidracon longimanus source

Interview:

Amy Atwater, a paleontologist and science communicator, the Director of Paleontology at Friends of Dinosaur Ridge in Morrison, Colorado, co-host of the podcast Weird & Dead, and author of the book “The Fossil Keeper’s Treasure”. Follow her @Mary_Annings_Revenge

Sponsors:

The dinosaur of the day: Mochlodon

• Rhabdodontid dinosaur that lived in the Late Cretaceous in what is now Austria and Hungary
• Rhabdodontids lived on a chain of islands in the Late Cretaceous in what is now Europe
• Rhabdodontids were herbivores that walked on two legs, had stocky bodies, strong legs, short arms, and long tails, and triangular skulls with narrow snouts
• Considered to be small to medium in size
• Had strong jaws, large teeth, and a pointy beak, so probably ate tough plants
• Rhabdodonts were some of the most common herbivorous dinosaurs from the Late Cretaceous of what is now Europe
• There are six genera and nine species
• Fossils of Mochlodon found in 1859
• Two species: Mochlodon suessi and Mochlodon vorosi
• Not named after paleontologist Hans Sues, but after a geologist, Eduard Suess
• Fossils found include an upper jaw (dentary), two vertebrae (that were lost), a skull bone, part of the shoulder, arm, and hand, and part of the leg
• Geologists Eduard Suess and Ferdinand Stoliczka led a team after a coal administrator let the University of Vienna know fossils had been found in a mine at Muthmannsdorf, Austria
• Fossils weren’t described until 1871, and at first considered to be Iguanodon
• Dr. Emanuel Bünzel named it as a new species of Iguanodon: Iguanodon suessii
• Iguanodon for a long time was a “wastebasket taxon”, so lots of dinosaurs at first considered to be Iguanodon
• Harry Seeley named it Mochlodon in 1881
• Type species is Mochlodon suessii
• Genus name means “bar tooth” and refers to the bar-like ridge on the middle of each tooth
• Mochlodon was sometimes considered to be a nomen dubium
• Franz Nopsca found the fossils of Rhabdodon and Mochlodon to be similar, and eventually found them all to be Rhabdodon
• Nopsca did name Mochlodon robustum (later became Mochlodon robustus) that in 2003 was renamed Zalmoxes robustus
• Some studies found no clearly defined differences between Mochlodon and Zalmoxes, so they may be the same dinosaur
• In 2012, a second species, Mochlodon vorosi, was named based on fossils found in Hungary. Described in 2012 by Attila Osi and others (oldest known rhabdodontid by 15 million years)
• The 2012 paper that named Mochlodon vorosi found both Mochlodon suessi and Mochlodon vorosi to be valid
• Compared to Zalmoxes, and based on histology, helps show Zalmoxes was not a dwarf dinosaur
• Both Mochlodon and Zalmoxes lived on islands, however Mochlodon was even smaller
• Found that the ancestral rhabdodontid had a femur lengths of 298–339 mm, which is close in size to the femur of Zalmoxes (which ranged from 320 to 333 mm)
• Mochlodon specimens that are about 3.9 to 5.9 ft (1.2 to 1.8 m) long have features that indicate they are adults. However, late juvenile Zalmoxes specimens are about 6.5 ft (2 m) long
• A 2022 study of microwear on the teeth found Mochlodon ate plants on the ground or low to the ground that were tough
• Based on tooth wear patterns, Mochlodon ate tougher plants than Hungarosaurus (which it lived alongside), based on its teeth wearing down more than twice the rate of Hungarosaurus’ teeth
• A 2023 study found that Mochlodon changed from quadrupedal to bipedal as it grew up
• Other animals Mochlodon suessi lived alongside include the nodosaur dinosaur Struthiosaurus crocodyliforms, turtles, and pterosaurs
• Other animals Mochlodon vorosi lived alongside include the nodosaurs Hungarosaurus and Struthiosaurus, as well as abelisaurids, sauropods, fish, amphibians, crocodyliforms, turtles, and pterosaurs

Fun Fact:

There’s a group of animals known as monstersaurs (they’ve lived from the time of dinosaurs to now) and a newly named one of them is named for a goblin king

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