Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates

Bibliographic Details
Main Author:	Zhang, Yue
Language:	English
Published:	The Ohio State University / OhioLINK 2015
Subjects:	Paleontology
Online Access:	http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679

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spelling	ndltd-OhioLink-oai-etd.ohiolink.edu-osu14310696792021-08-03T06:31:13Z Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates Zhang, Yue Paleontology Multituberculates are an extinct mammalian group that has its geological time span from at least the Late Jurassic to the latest Eocene, with fossils on all continents except Antarctica. Before the K-Pg boundary, in most North American Late Cretaceous mammalian faunas, multituberculates outnumbered eutherians and metatherians in both abundance and species richness. After the K-Pg boundary, the taxonomic diversity of multituberculates was succeeded by placental mammals. Multituberculates have unique dentition morphology differing from all extant mammals. Despite the importance of multituberculates in the study of mammalian evolution, much less is known about this enigmatic mammalian lineage compared to our knowledge of therian mammals. My dissertation mainly discusses the phylogenetics of Neoplagiaulacidae, the taxonomically richest family of multituberculates, and reconstructs the diets of cimolodontans (multituberculates from the Late Cretaceous to Paleogene) based on analyses of tooth wear, cusp charpness, and tooth size proportions.My phylogenetic study of neoplagiaulacids use a novel method proposed by me, the standardized character weighting approach. In this method, the variable range of character steps in each different character is set to the same scale. This new method has great superiority compared to the traditional parsimony method, in eliminating character state delimitation problem, finding the most balanced phylogenetic signals among conflicts, and not losing any evidence. The phylogenetic analysis of neoplagiaulacids reveals the evolution pattern of neoplagiaulacids on both large and small scales. The result shows that different lineages had different pathways of morphological specialization and a tendency of convergent evolution in acquiring larger ultimate lower premolar (p4). The result also indicates that ptilodontids were most likely derived from Parectypodus armstrongi. For the diet reconstruction of cimolodontans using multiple lines of evidence, the tooth wear patterns of the ultimate premolars (p4 and P4) are analyzed to infer the tooth function and chewing mechanism, the cusp sharpness on molars are linked with the physical perporty of food items, and the tooth size proportions are used to infer the developmental mode, which further reveals diet signal. The result indicates that the method presented here using combined evidence is robust in inferring the diet of cimolodontans. In the end, the tooth size proportions of multituberculates are compared to that of placental mammals, demonstrating that the lesser radiation and subsequent declination of multituberculates following the K-Pg boundary is correlated with less developmental plasticity of multituberculate teeth compared to that of placental mammals. 2015-08-17 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679 http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679 unrestricted This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center.
collection	NDLTD
language	English
sources	NDLTD
topic	Paleontology
spellingShingle	Paleontology Zhang, Yue Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
author	Zhang, Yue
author_facet	Zhang, Yue
author_sort	Zhang, Yue
title	Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
title_short	Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
title_full	Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
title_fullStr	Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
title_full_unstemmed	Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates
title_sort	phylogenetics of neoplagiaulacidae (multituberculata, mammalia), and diet reconstruction on cimolodontan multituberculates
publisher	The Ohio State University / OhioLINK
publishDate	2015
url	http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679
work_keys_str_mv	AT zhangyue phylogeneticsofneoplagiaulacidaemultituberculatamammaliaanddietreconstructiononcimolodontanmultituberculates
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Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates

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