Peiropemys mezzalirai, Gaffney & Meylan & Wood & Simons & De Almeida Campos, 2011

Gaffney, Eugene S., Meylan, Peter A., Wood, Roger C., Simons, Elwyn & De Almeida Campos, Diogenes, 2011, Evolution Of The Side-Necked Turtles: The Family Podocnemididae, Bulletin of the American Museum of Natural History 2011 (350), pp. 1-237 : 23-24

Peiropemys mezzalirai , n. gen. et sp.

TYPE SPECIMEN: MCT 1497-R (figs. 15– 18). This skull is a well-preserved and nearly complete specimen, lacking the right maxilla-jugal area and most of the premaxillae. The only parts unknown from one side or the other is the labial ridge area of the premaxilla, which is missing on both sides, and the distal edges of the pterygoid flange. The cavum cranii has been cleaned out, and the skull is free of most matrix. No crushing or distortion is visible.

TYPE LOCALITY: Caiera Quarry (of Campos and Kellner, 1999, and Kellner et al., 2005; same locality is ‘‘outcrop 1’’ of Carvalho et al., 2004, and Novas et al., 2008; ‘‘Point 1’’ of Ribeiro and Carvalho, 2007), at the southern end of the hill, Serra do Veadinha, near the old railroad station of Peirópolis, near the city of Uberaba (Municipality of Uberaba or Uberaba County), Minas Gerais State, Brazil. MCT 1497-R, type of Peiropemys mezzalirai , n. gen. et sp., was collected in 1959 by a team led by L.I. Price, DNPM, from the area excavated in that year as shown on the quarry map in Kellner et al. (2005: fig. 3).

Caiera Quarry , or Locality/Outcrop 1, has also yielded MCT 1498-R (the skull here named Pricemys caiera , n. gen. et sp.), MCT 1499-R (a large, nearly complete, shell of Peirópolis A), and many disarticulated turtle elements, here informally referred to as Peirópolis A and Peirópolis B.

According to Kellner et al. (2005), the original fossils from Caiera Quarry were found in 1947, with the main collecting efforts being in 1949, 1950, 1953, 1955, 1957, 1958, 1959, and 1961 (based on the published Caiera Quarry map in the DGM done under L.I. Price’s direction, Kellner et al., 2005: fig. 3). Original discoveries apparently date back to 1945 when L.I. Price responded to reports of fossil discoveries made during the construction of a railway at Mangabeira, north of Uberaba ( Ribeiro and Carvalho, 2007). During the time this quarry was in operation, a large number of fossils were collected, and over 185 square meters of the fossiliferous layer were exposed ( Ribeiro and Carvalho, 2007: figs. 1, 2). Although the work at Caiera Quarry was apparently ended in 1961, there was later collecting around the base of the same hill, Serra do Veadinha, and in the same stratigraphic unit, Serra da Galga Member, Marília Fm., that held the initial quarry. D.A. Campos and L.I. Price in 1967 and 1969 collected turtles in this area, according to labeled specimens. Collections have continued to be made in this area and a paleontological museum has been built near the site ( Ribeiro and Carvalho, 2007).

Other faunal elements from the Caiera Quarry include the prominent sauropods, but a frog, a lizard, crocodiles, and theropods, are also described or referenced in Carvalho et al. (2004), Kellner et al. (2005), Salgado and Carvalho (2008), Novas et al. (2008), and Candeiro (2009).

HORIZON: Serra da Galga Member, Marília Fm. (see Candeiro, 2009, and references).

DIAGNOSIS: As for genus.

ETYMOLOGY: For Sérgio Mezzalira, a DNPM geologist and invertebrate paleontologist who was very active in exploration and study of the Bauru Group and São Paulo State geology.

REFERRED MATERIAL: None. However, it is possible that the shell taxon informally referred to here as Peirópolis B belongs to Peiropemys . Peirópolis B is the smallest of the three shell taxa from this locality and the one for which there is the most limited amount of material. The material is all disarticulated (figs. 92, 93, 95, 97), but some of it is associated. At present we have the nuchal, costals 1, 5, 7, and 8, peripherals 1 and 8–11, the suprapygal, and pygal. We cannot assign any plastron material to this taxon at this time, although, based on size and a different morphology than in Peirópolis A, we speculate that some of the smaller plastral elements may belong to this species. Cambaremys langertoni , found near the Caiera Quarry , is apparently a juvenile ( França and Langer, 2005; Romano et al., 2009), and its small size may not be characteristic of the species. As far as we know at present, although the type and only known specimen of Cambaremys langertoni was found near the Caiera Quarry , only two taxa of turtles definitely occur in the quarry site. These are Peiropemys and Pricemys , based on skulls, and Peirópolis A and Peirópolis B, based on shells.

PREVIOUS WORK: Possibly the material referred to in Broin (1991: 515).

DISCUSSION: Peiropemys is the sister group to Pricemys + Lapparentemys in our analysis. These three genera are the sister taxon to all other podocnemidids, except Bauruemys , which is outside ( Peiropemys ( Pricemys , Lapparentemys )) and is the sister taxon to all podocnemidids. The morphology of these four genera and the Recent Podocnemis has ‘‘remained in all particulars in a pristine and unmodified condition (at least as regards their structure) through a grievous long period of time on Earth…’’ (Tedwelle in Gaffney, 1979: 69).