[dinosaur] Karoo (South Africa) Permian tetrapod oxygen isotopes and ecological inferences

Ben Creisler
[email protected]


DML server issues seem to be fixed (I had problems posting to the list
yesterday).

A new paper:

Kévin Rey, Michael O. Day, Romain Amiot, François Fourel, Julie Luyt, Marc
J. Van den Brandt, Christophe Lécuyer & Bruce S.Rubidge  (2019)
Oxygen isotopes and ecological inferences of Permian (Guadalupian)
tetrapods from the main Karoo Basin of South Africa.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online
publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.palaeo.2019.109485&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=PC3F7TH52BoglhC--0MKcxEVn_UzfcAownA9J4THsXg&s=e0IqVeAZ8ixVbkdG6aRRnCL4Dx-jFPkHR-0jUccb__U&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_abs_pii_S0031018219308454&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=PC3F7TH52BoglhC--0MKcxEVn_UzfcAownA9J4THsXg&s=OPtEo5vcdzIvmbh2PRz-_Q42_Mg8V4p_vuqUUBBNL6Y&e= 


Highlights

First application of δ18Op of apatite to South African tetrapods for
paleoecology
The lifestyle of middle Permian pareiasaurs is strongly shown to be
terrestrial.
The carnivorous dinocephalian Anteosaurus was probably living a terrestrial
ecology.
Knowing the ecology of major species helps understand the nature of the
extinction.

Abstract

The Abrahamskraal Formation of South Africa has a diverse middle Permian
(Guadalupian) fossil tetrapod fauna comprising largely basal therapsids and
pareiasaurian parareptiles. Knowledge on the paleoecology of these animals
is limited because inferences of many ecological traits in mid-Permian
tetrapods are based on deductions from morphology. While it is widely
accepted that the rhinesuchid amphibians were aquatic, the ecological
lifestyle of pareiasaurs and dinocephalian therapsids remains uncertain. To
investigate the ecological roles of different middle Permian tetrapod taxa
we studied stable oxygen isotope compositions of phosphate from teeth and
bones as a proxy for water dependence. Our results reveal similar δ18Op
values for pareiasaurs, the dinocephalian Anteosaurus, and therocephalians,
with a range of values similar to those of extant terrestrial species. The
consistent δ18Op values for pareiasaurs strengthen our interpretation of a
terrestrial lifestyle for these parareptiles, but the lower Anteosaurus
δ18Op values might question the interpretation and a larger sample size may
result in a more conclusive outcome. These results conclude the debate on
the ecology of middle Permian pareiasaurs. A terrestrial lifestyle is
applicable only to the middle Permian species and a different lifestyle is
possible for pareiasaurs species that lived after the end Capitanian
extinction.

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