New land tortoises (Testudines: Testudinidae) from the Miocene of Africa

The described fossil testudinids from the Miocene of Africa are reviewed. Geochelone stromeri sp. nov . is described from Lower Pliocene (Langebaanweg) and Miocene (Namib) specimens. Kinixys erosa , an extant species, is reported from Songhor Hill. Chersina sp. is reported from Arrisdrift. Impregnochelys pachytectis gen. et sp. nov . is described from Rusinga Island, Kenya, and is unique in having the anterior shell opening orientated ventrally and in having struts on the internal surface of the neurals, but shares with Kinixys a unique epiplastron shape, a high number of axillary scutes and unique orientation of the head of the femur.     

AFLP analysis shows high incongruence between genetic differentiation and morphology‐based taxonomy in a widely distributed tortoise

Morphology has traditionally been used to diagnose the taxa of various taxonomic ranks. However, there is growing evidence that morphology is not always able to reveal cryptic taxa, and that pronounced morphological variation could reflect phenotypic plasticity rather than evolutionary divergence. Spur‐thighed tortoises (the Testudo graeca complex), distributed in the western Palaearctic region, are characterized by high morphological variability and complicated taxonomy, which are under debate. Previous molecular studies using mainly mitochondrial DNA (mtDNA) sequences have revealed incongruence between genetic differentiation and morphology‐based taxonomy, suggesting that morphological variability is the result of phenotypic plasticity and stabilizing selection, which masks the true genealogies. In the present study, we used a range‐wide sampling and nuclear Amplified fragment length polymorphism (AFLP) markers to investigate genetic differentiation within the T. graeca complex. We found that spur‐thighed tortoises are differentiated into four geographically well‐defined AFLP groups: Balkans–Middle Eastern, western Mediterranean, Caucasian and central‐eastern Iranian. Compared with the distribution of mtDNA lineages, the groups are largely concordant, although the AFLP markers are less sensitive and distinguish fewer groups than do mtDNA sequences. The AFLP groups show an allopatric or parapatric distribution. The AFLP differentiation conflicts with the previously proposed morphology‐based taxonomy of the complex, suggesting that local adaptation to different environmental conditions may have led to the great extent of morphological variation within the same lineages. We propose a re‐evaluation of the taxa that were confirmed genetically using a thorough morphological analysis corrected for phenotypic plasticity. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●● , ●●–●●.     

THE TYPE SERIES OF 'SINEMYS'WUERHOENSIS, A PROBLEMATIC TURTLE FROM THE LOWER CRETACEOUS OF CHINA, INCLUDES AT LEAST THREE TAXA

Abstract:  We re-examine the type series of ' Sinemys ' wuerhoensis Yeh (at least 20 specimens, including several shells and skulls on three slabs of matrix and one isolated skull) from the Early Cretaceous Tugulu Group of China. Our study shows that the type series of ' S. ' wuerhoensis is actually a chimera made up of at least three distinct taxa. The holotype of this taxon should be assigned to the basal eucryptodire genus Xinjiangchelys Yeh. As there are no characters that distinguish ' S. ' wuerhoensis from Xinjiangchelys species, we consider it to be a nomen dubium . This new assignment of ' S. ' wuerhoensis expands the temporal range of Xinjiangchelys from the Late Jurassic into the Early Cretaceous in Asia. The majority of the paratypes of ' S. ' wuerhoensis (several shells in dorsal and ventral aspect and skulls) are referred to the basal eucryptodire genus Ordosemys Brinkman and Peng. We establish a new name for these specimens, Ordosemys brinkmania sp. nov. One additional specimen in the type series of ' S. ' wuerhoensis , a skull, is referred to cf. Pantrionychia Joyce, Parham and Gauthier indet.     

Hesperotestudo (Testudines: Testudinidae) from the Pleistocene of Bermuda, with comments on the phylogenetic position of the genus

A recently discovered fossil land tortoise (Testudines: Testudinidae) is described from the Pleistocene of Bermuda. Its morphology is sufficiently well preserved to allow assignment to the extinct North American genus Hesperotestudo. However, several features of this tortoise are unique and it is named Hesperotestudo bermudae sp. nov. A review of the phylogenetic relationships of the better known genera of the Testudinidae suggests that the affinities of Hesperotestudo lie with other North American tortoises (Gopherus) and not with Geochelone or other testudinines; thus, Hesperotestudo is reassigned to the Xerobatinae. This is at least the fifth documentation of a testudinid dispersing over open ocean to an oceanic island (the first for Hesperotestudo) and it corroborates the hypothesis that members of this family are well suited to over-water dispersal.     

Bergmann's and Rensch's rules and the spur‐thighed tortoise (Testudo graeca)

Body size is an ecologically important variable in animals. The geographical size variation of most snakes and some lizards counters Bergmann's rule in that, among related taxa, the larger ones live at warmer latitudes. However, exceptions notwithstanding, and despite being ectothermic, turtles as a group tend to obey Bergmann's rule. We examined this idea in Testudo graeca, ranging from Morocco to Romania and to Iran with disputed systematics, both at the global scale (using literature) and within the focal area of Israel (using museum specimens). Both globally and locally, carapace length correlated with latitude, in accordance with Bergmann's rule. The scant data on reproduction fully support the hypothesis that Bergmann's rule enables larger clutches where the climate would limit repeated clutches. The sexual size dimorphism (SSD) was approached using two methodologies: (1) ‘conventional’, using globally literature data and locally museum samples and (2) ‘innovated’, using photographs of copulating tortoises from Israel and Turkey. By each methodology, SSD emerged as being male biased in the larger‐bodied populations and female biased in the smaller‐bodied populations, obeying Rensch's rule. Some observations support the hypothesis that the evolution of large males serves intermale combating. Finally, Rensch's rule was found to apply separately within Anatolia and within the Levant, possibly indicating that these populations are separate.     

Turtle Shell Impression in a Coprolite from South Carolina,USA

Coprolites (fossilized feces) can preserve a wide range of biogenic components. A mold of a hatchling turtle partial shell (carapace) referable to Taphrosphys sulcatus is here identified within a coprolite from Clapp Creek in Kingstree, Williamsburg County, South Carolina, USA. The specimen is the first-known coprolite to preserve a vertebrate body impression. The small size of the turtle shell coupled with the fact that it shows signs of breakage indicates that the turtle was ingested and that the impression was made while the feces were still within the body of the predator. The detailed impression could only have survived the act of defecation if the section of bony carapace was voided concurrently and remained bonded with the feces until the latter lithified. Exceptionally, the surface texture of the scutes is preserved, including its finely pitted embryonic texture and a narrow perimeter of hatchling scute texture. The very small size of the shell represented by the impression makes it a suitable size for swallowing by any one of several large predators known from this locality. The coprolite was collected from a lag deposit containing a temporally mixed vertebrate assemblage (Cretaceous, Paleocene and Plio-Pleistocene). The genus Taphrosphys is known from both sides of the Cretaceous–Paleogene (K–Pg) boundary so, based on the size of the coprolite and the locally-known predators, the juvenile turtle could have been ingested by a mosasaur, a crocodylian, or a theropod dinosaur. Unlike mosasaurs and theropod dinosaurs, crocodylian stomachs have extremely high acid content that almost always dissolves bone. Therefore, the likely predator of this turtle was a mosasaur or a (non-avian or avian) theropod dinosaur.