Journal article
Earliest Onychophoran in Amber Reveals Gondwanan Migration Patterns



Publication Details
Authors:
de Sena Oliveira, I.; Bai, M.; Jahn, H.; Gross, V.; Martin, C.; Hammel, J.; Zhang, W.; Mayer, G.
Publisher:
CELL PRESS
Publication year:
2016
Journal:
Current Biology
Pages range:
2594-2601
Volume number:
26
Start page:
2594
End page:
2601
Number of pages:
8
ISSN:
0960-9822

Abstract
The anomalous occurrence of supposedly Gondwanan taxa in Laurasian-derived regions remains an intriguing chapter of paleobiogeographical history. Representatives of Peripatidae, a major subgroup of velvet worms (Onychophora), show a disjointed distribution in the neotropics, tropical Africa, and Southeast Asia, the latter being the only landmass previously associated with Laurasia [1, 2]. The arrival of these animals in Southeast Asia is explained by two alternative, albeit not mutually exclusive, hypotheses: an early migration via Europe before continental drift (Eurogondwana hypothesis) or transportation via insular India during the Cretaceous and Paleogene ("out-of-India" hypothesis) [3-6]. The latter hypothesis is based on a single extant species of Peripatidae, Typhloperipatus williamsoni, in India. dagger Cretoperipatus burmiticus from Myanmar is the oldest fossil onychophoran found in amber [7], dating to sometime between the two proposed scenarios, and hence crucial for clarifying how Gondwanan lineages of these low-vagility animals reached Southeast Asia (see also Supplemental Information). Based on the anatomical reconstruction of dagger C. burmiticus using synchrotron radiation-based X-ray microtomography (SR mu CT) and comparisons with extant taxa, we resolved this fossil species within Onychophora, particularly within Peripatidae, with T. williamsoni as its closest extant relative. This suggests that an early Eurogondwanan migration of peripatids was the most likely event, as Burmese amber is too old to be compatible with the out-of-India hypothesis. Moreover, peripatids probably colonized India only recently from Myanmar, refuting the putative Gondwanan relict status of Indian onychophorans. Finally, preservation artifacts identified in the novel amber material might have a major impact on studies of onychophoran stem and/or crown groups.

Last updated on 2019-25-07 at 16:13