Parallel evolution of hand anatomy in kangaroos and vombatiform marsupials: functional and evolutionary implications

Weisbecker, Vera and Archer, Michael (2008) Parallel evolution of hand anatomy in kangaroos and vombatiform marsupials: functional and evolutionary implications. Palaeontology, 51 2: 321-338. doi:10.1111/j.1475-4983.2007.00750.x


Author Weisbecker, Vera
Archer, Michael
Title Parallel evolution of hand anatomy in kangaroos and vombatiform marsupials: functional and evolutionary implications
Journal name Palaeontology   Check publisher's open access policy
ISSN 0031-0239
1475-4983
Publication date 2008-03
Sub-type Article (original research)
DOI 10.1111/j.1475-4983.2007.00750.x
Volume 51
Issue 2
Start page 321
End page 338
Total pages 18
Place of publication West Sussex, United Kingdom
Publisher Wiley-Blackwell
Language eng
Abstract The anatomy of the mammalian hand is exposed to an intriguing interplay between phylogeny and function, and provides insights on phylogenetic affinities as well as locomotory habits of extinct species. Within the marsupial order Diprotodontia, terrestrial plantigrade quadrupedalism evolved twice, in the mostly extinct vombatiforms and in extant macropodoids. To assess the influence of functional and phylogenetic signal on the manus in these two clades, manual anatomy and digital proportions in specimens of eight extinct and three extant vombatiforms were investigated and compared with extant macropodoids and extant possums. The results reveal extensive parallelisms in the carpal region of vombatiforms and macropodoids, including flattened distal metacarpal facets, reduction of the palmar process of the hamatum, reduction of mid-wrist joint curve, extensive hamatum/scaphoid contact, and absence of a lunatum. These transformations appear to be related to stabilization of the wrist for plantigrade locomotion. Vombatiforms are apomorphic in scaphoid and triquetrum anatomy and their metacarpals are much more gracile than in other Diprotodontia. Manual diversity is greater in vombatiforms than in macropodoids, as probably was locomotor diversity. Digital proportions as well as wrist anatomy divide the extinct vombatiforms into species resembling arboreal diprotodontians, whereas others group with terrestrial quadrupedal kangaroos and wombats. The latter is suggested to be owing to plantigrade locomotion and/or large size. Carpal anatomy and digital proportions suggest that a range of earlier diverging vombatiforms may have been arboreal or scansorial. As such, we propose that the ancestor of extant vombatiforms (koalas and wombats) may have been arboreal, an option that deserves consideration in the reconstruction of vombatiform evolution.
Keyword Diprotodontia
Vombatiformes
Manus
Convergence
Plantigrade
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 14 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 15 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Mon, 08 Apr 2013, 22:44:25 EST by Gail Walter on behalf of Scholarly Communication and Digitisation Service