Episode 360 is all about Naashoibitosaurus, a New Mexican relative of Edmontosaurus from the Late Cretaceous.
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In this episode, we discuss:
News:
- The new dinosaur that resembles a miniature Coelophysis, Pendraig, was found in Wales source
- The President of the USA restored environmental protections at Bears Ears and Grand Staircase-Escalante monuments in Utah source
- In New Jersey, Rowan University broke ground on the dinosaur fossil park museum at the Marl Quarry source
- The Royal Belgian Institute of Natural Sciences has a T. rex exhibit featuring a 3D cast replica of Trix source
- A 14 year-old girl in India, is India’s youngest paleontologist having collected 136 fossils in 4 years source
- One of the most searched for terms for costumes is “dinosaur” source
The dinosaur of the day: Naashoibitosaurus
- Saurolophine hadrosaurid that lived in the Late Cretaceous in what is now New Mexico, US (Kirtland Formation)
- Herbivorous, and had dental batteries with hundreds of teeth
- Cropped plants with its beak
- Had a nasal arch that rose above the front of the eyes
- Type species is Naashoibitosaurus ostromi
- Genus name means “Creek lizard”
- Was thought to be found in the Naashoibito Member of the Kirtland Formation (now considered to be part of the Ojo Alamo Formation)
- Later, found to be from an older part of the formation, De-na-zin Member (a few million years older)
- Species name in honor of Ostrom “for his work on the cranial morphology of hadrosaurs and for describing one of the taxa from the San Juan Basin”
- Partial skeleton found, and parts of the skull
- Part of the holotype found in the 1970s and 1980s
- Holotype is a large portion of the skull, portion of an articulated cervical series (unprepared), a right humerus, several ribs, and maybe two dorsal vertebrae (questionably included)
- First described as Kritosaurus by Jack Horner, when he described two hadrosaur skulls in 1992
- Hunt and Lucas in 1992, unaware of Horner’s study, had described a lot of the skull and postcrania as Edmontosaurus saskatchewanensis
- Named in 1993 by Adrian Hunt and Spencer Lucas
- Reassigned the postcrania to Naashoibitosaurus and included one of Horner’s skulls in the holotype
- Hunt and Lucas said specimen could not be Edmontosaurus based on the morphology of the skull roof
- Hunt and Lucas said Kritosaurus navajovius was a nomen dubium
- Said Kritosaurus holotype was a poor specimen (missing parts of the skull that have most of the diagnostic features of hadrosaurs)
- In 1993 they named two new genera based on the two hadrosaur skulls Horner described
- One was a skull roof from what they thought came from the Naashoibito Member
- Said the two hadrosaur skulls were from different stratigraphic units (other skull named Anasazisaurus, from the pre-Naashoibito Kirtland)
- Also no evidence they were the same taxon or ontogenetic variants of each other (growth series)
- Hence the two names
- In 2000 Thomas Williamson reexamined the holotype of Kritosaurus navajovius and found it to be valid and “the senior subjective synonym of both Anasazisaurus horneri and Naashoibitosaurus ostromi”
- Said Naashoibitosaurus was not distinguished based on morphological grounds, and that it came from approximately the same stratigraphic horizon and part of similar faunas to Anasazisaurus and Kritosaurus navajovius
- In 2013 Albert Prieto-Márquez found Naashoibitosaurus to be distinct but that Anasazisaurus was a synonym of Kritosaurus, but kept it as a distinct species: Kritosaurus horneri
- Other dinosaurs that lived around the same time and place include Nodocephalosaurus, Parasaurolophus, Pentaceratops, Sphaerotholus, Ziapelta, Daspletosaurus, Ornithomimus, Saurornitholestes
Fun Fact: Pendraig milnerae is the third dinosaur named after Angela Milner.
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