Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Phylogenetics of characters and groups, and the classification of taxa
- 3 Problems in understanding metatherian evolution
- 4 Form–function, and ecological and behavioral morphology in Metatheria
- 5 Background to the analysis of metatherian cruropedal evidence
- 6 Mesozoic and Cenozoic: Fossil tarsals of ameridelphians unassociated with teeth
- 7 Cruropedal attributes of living and fossil families of metatherians
- 8 Taxa and phylogeny of Metatheria
- 9 Paleobiogeography and metatherian evolution
- References
- Index
6 - Mesozoic and Cenozoic: Fossil tarsals of ameridelphians unassociated with teeth
Published online by Cambridge University Press: 16 October 2009
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Phylogenetics of characters and groups, and the classification of taxa
- 3 Problems in understanding metatherian evolution
- 4 Form–function, and ecological and behavioral morphology in Metatheria
- 5 Background to the analysis of metatherian cruropedal evidence
- 6 Mesozoic and Cenozoic: Fossil tarsals of ameridelphians unassociated with teeth
- 7 Cruropedal attributes of living and fossil families of metatherians
- 8 Taxa and phylogeny of Metatheria
- 9 Paleobiogeography and metatherian evolution
- References
- Index
Summary
Are the Deltatheriidae marsupials? Their upper molar patterns, with broad stylar shelf and well developed stylocone, resemble some late Cretaceous Didelphidae more than Palaeoryctidae.
Butler and Kielan-Jaworowska (1973, p. 106)The deltatheriid postcanine formula is logically irrelevant to refutation of the hypothesis of marsupial affinities for the Pediomyidae … It is clear … that the reduction in the stylar [area] on upper molars of the Pediomyidae and ‘dog-like marsupials [i.e., borhyaenoids] was generated independently, from very different demands of natural selection in the two groups, and that the one pattern had nothing whatever to do with the other in either a functional or genealogical sense’.c
Fox (1979c, pp. 733–5)North America, Europe, Asia, and Africa
The convincing case made recently by Kielan-Jaworowska and Nessov (1990) for the metatherian affinities of the Deltatheroida of the Early to Late Cretaceous of Asia (and possibly also of North America) will be reviewed in Chapter 8 along with the less convincing suggestion of Kielan-Jaworowska (1992) for aegialodontian-deltatheroidan ancestor-descendant relationships. The postcranial anatomy of some deltatheroidan species is currently being described (Szalay & Nessov, in preparation), and a new group of Asian metatherians represented by the late Cretaceous Asiatherium (nomen nudum, Trofimov & Szalay, 1993) is discussed elsewhere (in preparation). A discussion of the relationships of the described taxa is presented in Chapter 8 under “Theria” and “Metatheria.”
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- Publisher: Cambridge University PressPrint publication year: 1995