Post by surroundx on Sept 22, 2015 11:11:34 GMT
First Asian record of a late Pleistocene reduncine (Artiodactyla, Bovidae, Reduncini), Sivacobus sankaliai, sp. nov., from Gopnath (Miliolite Formation) Gujarat, India, and a revision of the Asian genus Sivacobus Pilgrim, 1939
Abstract
The new species, Sivacobus sankaliai, from an assemblage dated <200 ka near Gopnath, northwestern India, constitutes the only record of the bovid tribe Reduncini (waterbuck and allies) outside Africa within ≤500 ka. The previous Asian reduncine record was assigned to at least six genera, with the latest known record from the Siwalik Pinjor Formation (India and Pakistan, ca. 2.7–0.6 Ma) and probably ≥1.7 Ma. Finding this unexpectedly late Asian reduncine prompted tests of two hypotheses: (1) the Gopnath form derives directly from an African lineage following immigration since 500 ka. (2) It is the last known survivor of an Asian monophyletic group. The evidence supports the second hypothesis. We find that Asian Plio–Pleistocene reduncines belong to only one genus, Sivacobus, of ≥3 Ma duration, and to only two species up to Pinjor times, S. palaeindicus and S. patulicornis, with now a third and later Pleistocene species added. We give a revised diagnosis of Sivacobus. There is a close, and probable sister-group, relationship of Sivacobus with Adenota, the African crown kob clade. Sivacobus arose from the same African ancestor as the kobs, which emigrated from Africa ca. 3.5 Ma ago and endured in Asia for ≥3 Ma. The African sister group survived to the present, whereas the Asian one almost did. The S. sankaliai discovery has resulted not only in an increase in morphological, taxonomic, and geographic diversity of the Asian Reduncini, but also—and importantly—in a significant extension of their duration.
Source:
Vrba, Elisabeth S, Bibi, Faysal and Costa, August G. (2015). First Asian record of a late Pleistocene reduncine (Artiodactyla, Bovidae, Reduncini), Sivacobus sankaliai, sp. nov., from Gopnath (Miliolite Formation) Gujarat, India, and a revision of the Asian genus Sivacobus Pilgrim, 1939. Journal of Vertebrate Paleontology 35(4): e943399. [Abstract]
Abstract
The new species, Sivacobus sankaliai, from an assemblage dated <200 ka near Gopnath, northwestern India, constitutes the only record of the bovid tribe Reduncini (waterbuck and allies) outside Africa within ≤500 ka. The previous Asian reduncine record was assigned to at least six genera, with the latest known record from the Siwalik Pinjor Formation (India and Pakistan, ca. 2.7–0.6 Ma) and probably ≥1.7 Ma. Finding this unexpectedly late Asian reduncine prompted tests of two hypotheses: (1) the Gopnath form derives directly from an African lineage following immigration since 500 ka. (2) It is the last known survivor of an Asian monophyletic group. The evidence supports the second hypothesis. We find that Asian Plio–Pleistocene reduncines belong to only one genus, Sivacobus, of ≥3 Ma duration, and to only two species up to Pinjor times, S. palaeindicus and S. patulicornis, with now a third and later Pleistocene species added. We give a revised diagnosis of Sivacobus. There is a close, and probable sister-group, relationship of Sivacobus with Adenota, the African crown kob clade. Sivacobus arose from the same African ancestor as the kobs, which emigrated from Africa ca. 3.5 Ma ago and endured in Asia for ≥3 Ma. The African sister group survived to the present, whereas the Asian one almost did. The S. sankaliai discovery has resulted not only in an increase in morphological, taxonomic, and geographic diversity of the Asian Reduncini, but also—and importantly—in a significant extension of their duration.
Source:
Vrba, Elisabeth S, Bibi, Faysal and Costa, August G. (2015). First Asian record of a late Pleistocene reduncine (Artiodactyla, Bovidae, Reduncini), Sivacobus sankaliai, sp. nov., from Gopnath (Miliolite Formation) Gujarat, India, and a revision of the Asian genus Sivacobus Pilgrim, 1939. Journal of Vertebrate Paleontology 35(4): e943399. [Abstract]