Phylogenetic placement of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar : implications for allotherian relationships

Hoffmann, S; Beck, RMD; Wible, JR; Rougier, GW; Krause, DW

Abstract

The phylogenetic position of Gondwanatheria within Mammaliaformes has historically been controversial. The well-preserved skeleton of Adalatherium hui from the Late Cretaceous of Madagascar offers a unique opportunity to address this issue, based on morphological data from the whole skeleton. Gondwanatheria were, until recently, known only from fragmentary dental and mandibular material, as well as a single cranium. The holotype of A. hui provides the first postcranial skeleton for gondwanatherians and substantially increases the amount of character data available to score. We sampled 530 characters and 84 cynodonts (including 34 taxa historically affiliated with Allotheria) to test the phylogenetic relationships of Gondwanatheria and Allotheria using parsimony, undated Bayesian, and tip-dated Bayesian methods. We tested three lower dental formulae for Adalatherium, because its postcanines are distinctly different from those of other mammaliaforms and cannot readily be homologized with any known dental pattern. In all analyses, Adalatherium is recovered within Gondwanatheria, most frequently outside of Sudamericidae or Ferugliotheriidae, which is congruent with establishment of the family Adalatheriidae. The different dental coding schemes do not greatly impact the position of Adalatherium, although there are differences in character optimization. In all analyses, Gondwanatheria are placed within Allotheria, either as sister to Multituberculata, nested within Multituberculata, or as sister to Cifelliodon (and Euharamiyida), or in a polytomy with other allotherians. The composition of Allotheria varies in our analyses. The haramiyidans Haramiyavia and Thomasia are placed outside of Allotheria in the parsimony and tip-dated Bayesian analyses, but in a polytomy with other allotherians in the undated Bayesian analyses.

Citation

Hoffmann, S., Beck, R., Wible, J., Rougier, G., & Krause, D. (2020). Phylogenetic placement of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar : implications for allotherian relationships. Journal of Vertebrate Paleontology, 40(Sup 1), 213-234. https://doi.org/10.1080/02724634.2020.1801706

• Journal Article Type: Article
• Acceptance Date: Apr 20, 2020
• Online Publication Date: Dec 18, 2020
• Publication Date: Dec 18, 2020
• Deposit Date: Jan 13, 2021
• Publicly Available Date: Dec 18, 2021
• Journal: Journal of Vertebrate Paleontology
• Print ISSN: 0272-4634
• Electronic ISSN: 1937-2809
• Publisher: Taylor and Francis
• Volume: 40
• Issue: Sup 1
• Pages: 213-234
• DOI: https://doi.org/10.1080/02724634.2020.1801706
• Publisher URL: https://doi.org/10.1080/02724634.2020.1801706
• Related Public URLs: http://www.tandfonline.com/loi/ujvp20
• Additional Information: Additional Information : ** From Crossref journal articles via Jisc Publications Router **Journal IDs: pissn 0272-4634; eissn 1937-2809 **History: published_online 18-12-2020; issued 30-10-2020; published 30-10-2020; Access Information : This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Vertebrate Paleontology on 18th December 2020, available online: http://www.tandfonline.com/10.1080/02724634.2020.1801706.; Funders : National Science Foundation;Agencia de Promoción Científica y Tecnológica, Argentina; Grant Number: DEB-1501497, DEB-1654949, EAR-1122642, EAR-1528273, and EAR-1664432; Grant Number: PICT-2016-3682