A new polyglyphanodontian lizard with a complete lower temporal bar from the Upper Cretaceous of southern China

Journal of Systematic Palaeontology, Journal Year: 2023, Volume and Issue: 21(1)

Published: Jan. 1, 2023

Polyglyphanodontians were a dominant terrestrial lizard group during the Cretaceous. They mainly distributed across Laurasia but show their greatest diversity in Upper Cretaceous deposits of China and Mongolia. Several Asian taxa comparatively large, with robust skulls dentition specialized for herbivory. Two polyglyphanodontian genera, Tianyusaurus from Polyglyphanodon North America, are unusual having developed complete, or near lower temporal bar. Here we describe third complete bar, Yechilacerta yingliangia gen. et sp. nov., Jiangxi Province, southern China. These have also yielded specimens Tianyusaurus, new genus differs several key aspects skull dental morphology, including presence coarse pustulate cranial sculpture, absence maxillary caniniform teeth. Phylogenetic analysis places species as sister taxon to both nested among East gilmoreteiids. Previous phylogenetic analyses using morphological characters mostly placed polyglyphanodontians close extant teiioid lizards, our analyses, constraint tree squamates based on published molecular phylogenies, Polyglyphanodontia closer Iguania. However, more comprehensive review is needed resolve relationships.

Language: Английский

Evolution of Hadrosaurs in the Campanian of Laramidia: New Information from the Skull Roof and Braincase

Published: Jan. 1, 2022

This project seeks to investigate the morphology, ontogeny, and evolution of skull roof braincase characters in hadrosaurids from Campanian northern Laramidia (Alberta Montana), a setting which they have been historically recognized as having high abundance diversity. New material is evaluated clarify distribution informativeness morphological character states, allow further testing previous hypotheses about how ontogenetic development these evolved within clades, enable identification previously unrecorded taxa. Five partial skulls Maiasaura peeblesorum are described bone bed Two Medicine Formation Montana, providing basis for description morphology this taxon, an series allowing crest be compared related new middle unit Oldman at Milk River Ridge Reservoir near Warner, southern Alberta both represent first occurrences taxon that unit. The diagnostic occurrence Canada. Brachylophosaurus example co-occurring brachylophosaurins. second Parasaurolophini, oldest lambeosaurine Alberta. A phylogenetic analysis using maximum parsimony Bayesian methods supports identifications, also re-identifies specimen Dinosaur Park geologically youngest brachylophosaurin

Language: Английский