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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.


Phylogenetic relations of Stereogenyina based on the single most parsimonious tree obtained in the present study.Node numbers are indicated above each node and GC bootstrap values above 40 in front of them. Squares indicate the synapomorphies of the respective clade (black = 0 to 1, gray = 0 to 2, white = 1 to 0).
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fig-5: Phylogenetic relations of Stereogenyina based on the single most parsimonious tree obtained in the present study.Node numbers are indicated above each node and GC bootstrap values above 40 in front of them. Squares indicate the synapomorphies of the respective clade (black = 0 to 1, gray = 0 to 2, white = 1 to 0).

Mentions: The newly described skull was coded into a taxon-character matrix using Mesquite v. 3.0 (Maddison & Maddison, 2014). The matrix includes 57 characters (nine of which are new and 48 previously proposed by various authors) (SI1; Bona & de la Fuente, 2005; Cadena et al., 2012; Dumont Júnior, 2013; de la Fuente, 2003; Gaffney, 1977; Gaffney, Tong & Meylan, 2006; Gaffney et al., 2011; Meylan, Gaffney & Campos, 2009; Thomson & Georges, 2009, and 16 taxa. Podocnemis unifilis (Troschel, 1848), Peltocephalus dumerilianus (Schweigger, 1812), Erymnochelys madagascariensis (Grandidier, 1867) and Mogharemys blackenhorni (Dacqué, 1912) formed the outgroup and twelve Stereogenyina were included in the ingroup. The resulting matrix was analysed in TNT v. 1.0 (Goloboff, Farris & Nixon, 2008) using parsimony and implicit enumeration algorithms and bootstrap values (GC, 1,000 replicates, Fig. 5; Goloboff et al., 2003) were calculated using TNT implemented functions. A second analysis was run in TNT with a positive constraint (using the command force) for the monophyly of all species previously assigned to Bairdemys, and the resulting suboptimal topology was compared with the most parsimonious tree (MPT) using the Templeton test (Templeton, 1983) in PAUP* v. 4.0 (Swofford, 2002) (Table 1).


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)

Phylogenetic relations of Stereogenyina based on the single most parsimonious tree obtained in the present study.Node numbers are indicated above each node and GC bootstrap values above 40 in front of them. Squares indicate the synapomorphies of the respective clade (black = 0 to 1, gray = 0 to 2, white = 1 to 0).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig-5: Phylogenetic relations of Stereogenyina based on the single most parsimonious tree obtained in the present study.Node numbers are indicated above each node and GC bootstrap values above 40 in front of them. Squares indicate the synapomorphies of the respective clade (black = 0 to 1, gray = 0 to 2, white = 1 to 0).
Mentions: The newly described skull was coded into a taxon-character matrix using Mesquite v. 3.0 (Maddison & Maddison, 2014). The matrix includes 57 characters (nine of which are new and 48 previously proposed by various authors) (SI1; Bona & de la Fuente, 2005; Cadena et al., 2012; Dumont Júnior, 2013; de la Fuente, 2003; Gaffney, 1977; Gaffney, Tong & Meylan, 2006; Gaffney et al., 2011; Meylan, Gaffney & Campos, 2009; Thomson & Georges, 2009, and 16 taxa. Podocnemis unifilis (Troschel, 1848), Peltocephalus dumerilianus (Schweigger, 1812), Erymnochelys madagascariensis (Grandidier, 1867) and Mogharemys blackenhorni (Dacqué, 1912) formed the outgroup and twelve Stereogenyina were included in the ingroup. The resulting matrix was analysed in TNT v. 1.0 (Goloboff, Farris & Nixon, 2008) using parsimony and implicit enumeration algorithms and bootstrap values (GC, 1,000 replicates, Fig. 5; Goloboff et al., 2003) were calculated using TNT implemented functions. A second analysis was run in TNT with a positive constraint (using the command force) for the monophyly of all species previously assigned to Bairdemys, and the resulting suboptimal topology was compared with the most parsimonious tree (MPT) using the Templeton test (Templeton, 1983) in PAUP* v. 4.0 (Swofford, 2002) (Table 1).

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.