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The last marine pelomedusoids (Testudines: Pleurodira): a new species of Bairdemys and the paleoecology of Stereogenyina.

Ferreira GS, Rincón AD, Solórzano A, Langer MC - PeerJ (2015)

Bottom Line: Here, we describe a new Stereogenyina species, based on an almost complete skull from the middle Miocene Capadare Formation, of Venezuela.Based on geometric morphometrics analyses, we related the development of the stereogenyin secondary palate with the acquisition of a durophagous diet.These two inferences allowed us to hypothesize that stereogenyins occupied an ecological niche similar to that of the extant Carettini sea turtles, and that the rise of the latter group may be related to the Stereogenyina diversity fall in the end of the Miocene.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Paleontologia de Ribeirão Preto, FFCLRP, Universidade de São Paulo , Ribeirão Preto, SP , Brazil.

ABSTRACT
The extinct Stereogenyina turtles form a relatively diverse Podocnemididae lineage, with twelve described and phylogenetically positioned species. They are characterized by a wide geographic and temporal range, from the Eocene of Africa to the Pleistocene of Southeast Asia, and a peculiar palate morphology, with a secondary palate that is unique among side-necked turtles. Here, we describe a new Stereogenyina species, based on an almost complete skull from the middle Miocene Capadare Formation, of Venezuela. A new phylogenetic analysis supports the assignment of the new species to the genus Bairdemys. Based on geometric morphometrics analyses, we related the development of the stereogenyin secondary palate with the acquisition of a durophagous diet. Based on a review of the sedimentary environments where their fossils are found, we also propose that stereogenyins were a marine radiation of podocnemidid turtles, as corroborated by previous studies of fossil eggs and limb morphology. These two inferences allowed us to hypothesize that stereogenyins occupied an ecological niche similar to that of the extant Carettini sea turtles, and that the rise of the latter group may be related to the Stereogenyina diversity fall in the end of the Miocene.

No MeSH data available.


Cladogram calibrated on a time scale and species diversity plot.Cladogram calibrated on a time scale (A and D) and species diversity plot based on the count of lineages on each age (B and C), from the Eocene to the present, for Stereogenyina (A and B) and Carettini turtles (C and D, cladogram based on Parham & Pyenson, 2010). Layout modified from Romano et al. (2014)).
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fig-8: Cladogram calibrated on a time scale and species diversity plot.Cladogram calibrated on a time scale (A and D) and species diversity plot based on the count of lineages on each age (B and C), from the Eocene to the present, for Stereogenyina (A and B) and Carettini turtles (C and D, cladogram based on Parham & Pyenson, 2010). Layout modified from Romano et al. (2014)).

Mentions: Bairdemys thalassica is closer to Bairdemys venezuelensis (node 27, Fig. 5) than to the other species of Bairdemys, sharing a moderately developed (caudally) palatine that reduces the contact between the pterygoids (car. 25, state 0 → 1) and a condylus mandibularis caudal or at the same line of the basioccipital-basisphenoid contact (car. 30, state 0 → 1). B. hartsteini is the sister taxon to this clade, followed by B. sanchezi and B. winklerae. This arrangement implies an early Miocene (Fig. 8A), rather than Oligocene (Weems & Knight, 2013) origin of Bairdemys.


The last marine pelomedusoids (Testudines: Pleurodira): a new species of Bairdemys and the paleoecology of Stereogenyina.

Ferreira GS, Rincón AD, Solórzano A, Langer MC - PeerJ (2015)

Cladogram calibrated on a time scale and species diversity plot.Cladogram calibrated on a time scale (A and D) and species diversity plot based on the count of lineages on each age (B and C), from the Eocene to the present, for Stereogenyina (A and B) and Carettini turtles (C and D, cladogram based on Parham & Pyenson, 2010). Layout modified from Romano et al. (2014)).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493680&req=5

fig-8: Cladogram calibrated on a time scale and species diversity plot.Cladogram calibrated on a time scale (A and D) and species diversity plot based on the count of lineages on each age (B and C), from the Eocene to the present, for Stereogenyina (A and B) and Carettini turtles (C and D, cladogram based on Parham & Pyenson, 2010). Layout modified from Romano et al. (2014)).
Mentions: Bairdemys thalassica is closer to Bairdemys venezuelensis (node 27, Fig. 5) than to the other species of Bairdemys, sharing a moderately developed (caudally) palatine that reduces the contact between the pterygoids (car. 25, state 0 → 1) and a condylus mandibularis caudal or at the same line of the basioccipital-basisphenoid contact (car. 30, state 0 → 1). B. hartsteini is the sister taxon to this clade, followed by B. sanchezi and B. winklerae. This arrangement implies an early Miocene (Fig. 8A), rather than Oligocene (Weems & Knight, 2013) origin of Bairdemys.

Bottom Line: Here, we describe a new Stereogenyina species, based on an almost complete skull from the middle Miocene Capadare Formation, of Venezuela.Based on geometric morphometrics analyses, we related the development of the stereogenyin secondary palate with the acquisition of a durophagous diet.These two inferences allowed us to hypothesize that stereogenyins occupied an ecological niche similar to that of the extant Carettini sea turtles, and that the rise of the latter group may be related to the Stereogenyina diversity fall in the end of the Miocene.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Paleontologia de Ribeirão Preto, FFCLRP, Universidade de São Paulo , Ribeirão Preto, SP , Brazil.

ABSTRACT
The extinct Stereogenyina turtles form a relatively diverse Podocnemididae lineage, with twelve described and phylogenetically positioned species. They are characterized by a wide geographic and temporal range, from the Eocene of Africa to the Pleistocene of Southeast Asia, and a peculiar palate morphology, with a secondary palate that is unique among side-necked turtles. Here, we describe a new Stereogenyina species, based on an almost complete skull from the middle Miocene Capadare Formation, of Venezuela. A new phylogenetic analysis supports the assignment of the new species to the genus Bairdemys. Based on geometric morphometrics analyses, we related the development of the stereogenyin secondary palate with the acquisition of a durophagous diet. Based on a review of the sedimentary environments where their fossils are found, we also propose that stereogenyins were a marine radiation of podocnemidid turtles, as corroborated by previous studies of fossil eggs and limb morphology. These two inferences allowed us to hypothesize that stereogenyins occupied an ecological niche similar to that of the extant Carettini sea turtles, and that the rise of the latter group may be related to the Stereogenyina diversity fall in the end of the Miocene.

No MeSH data available.