[Paleontology • 2015] Pappochelys rosinae • A Middle Triassic stem-Turtle and the Evolution of the Turtle Body Plan

Pappochelys rosinae Schoch & Sues, 2015

 doi: 10.1038/nature14472

The origin and early evolution of turtles have long been major contentious issues in vertebrate zoology. This is due to conflicting character evidence from molecules and morphology and a lack of transitional fossils from the critical time interval. The ~220-million-year-old stem-turtle Odontochelys from China has a partly formed shell and many turtle-like features in its postcranial skeleton. Unlike the 214-million-year-old Proganochelys from Germany and Thailand, it retains marginal teeth and lacks a carapace. Odontochelys is separated by a large temporal gap from the ~260-million-year-old Eunotosaurus from South Africa, which has been hypothesized as the earliest stem-turtle. Here we report a new reptile, Pappochelys, that is structurally and chronologically intermediate between Eunotosaurus and Odontochelys and dates from the Middle Triassic period (~240 million years ago). The three taxa share anteroposteriorly broad trunk ribs that are T-shaped in cross-section and bear sculpturing, elongate dorsal vertebrae, and modified limb girdles. Pappochelys closely resembles Odontochelys in various features of the limb girdles. Unlike Odontochelys, it has a cuirass of robust paired gastralia in place of a plastron. Pappochelys provides new evidence that the plastron partly formed through serial fusion of gastralia. Its skull has small upper and ventrally open lower temporal fenestrae, supporting the hypothesis of diapsid affinities of turtles. 

Figure 2: Skull elements of Pappochelys rosinae (digitally extracted from surrounding matrix). 
a, b, Left maxilla (SMNS 91431; a, labial view; b, lingual view of marked section); c, skull reconstruction in lateral view, with preserved elements indicated in grey; d, right parietal (SMNS 91356); e, right postorbital (SMNS 91356); f, right squamosal (SMNS 90013); g, right quadrate (SMNS 90013); h, left jugal (SMNS 92066, broken into two segments and partly preserved as an impression); i, left dentary (SMNS 92066).

 doi: 10.1038/nature14472

Figure 5: Early evolution of the turtle body plan.
a, Restoration of the skeleton of Pappochelys in lateral view (as yet unknown elements in white; preserved bones in grey; trunk ribs and gastralia highlighted in black); b, successive appearance of key features of the turtle body plan; c, plastron of Odontochelys and reconstructed ventral bones of the shoulder girdle and gastralia set in Pappochelys (elements of the shoulder girdle and their homologues are indicated in a darker shade of grey).

 doi: 10.1038/nature14472

Reptilia Laurenti, 1768

Pan-Testudines Joyce, Parham and Gauthier, 2004 

Pappochelys gen. nov.

Etymology. Pappos (Greek): grandfather; chelys (Greek): turtle. Type species. Pappochelys rosinae.

Pappochelys rosinae sp. nov.

Etymology. In honour of I. Rosin, who prepared key specimens of the new taxon.

Holotype. Staatliches Museum für Naturkunde Stuttgart, SMNS 91360, incomplete, partly articulated postcranial skeleton. 

Rainer R. Schoch and Hans-Dieter Sues. 2015. A Middle Triassic stem-Turtle and the Evolution of the Turtle Body Plan. Nature. (2015) doi: 10.1038/nature14472

Hero in a half-formed shell: Turtle ancestor with bony belly unearthed 

The fossil of Pappochelys, grew to around eight inches and lived along the shores of a lake in the Middle Jurassic period 240 million years ago. Palaeontologists say it was an early ancestor of modern turtles and the shape of its skull suggests these reptiles are more closely related to dinosaurs and birds than snakes 

http://dailym.ai/1LuMuxJ via @MailOnline

Älteste Schildkröte der Welt in Deutschland entdeckt.  https://idw-online.de/de/news633623

[Paleontology • 2014] Origin of the Unique Ventilatory Apparatus of Turtles

The turtle body plan differs markedly from that of other vertebrates and serves as a model system for studying structural and developmental evolution. Incorporation of the ribs into the turtle shell negates the costal movements that effect lung ventilation in other air-breathing amniotes. Instead, turtles have a unique abdominal-muscle-based ventilatory apparatus whose evolutionary origins have remained mysterious. Here we show through broadly comparative anatomical and histological analyses that an early member of the turtle stem lineage has several turtle-specific ventilation characters: rigid ribcage, inferred loss of intercostal muscles and osteological correlates of the primary expiratory muscle. Our results suggest that the ventilation mechanism of turtles evolved through a division of labour between the ribs and muscles of the trunk in which the abdominal muscles took on the primary ventilatory function, whereas the broadened ribs became the primary means of stabilizing the trunk. These changes occurred approximately 50 million years before the evolution of the fully ossified shell.

...........

Tyler R. Lyson, Emma R. Schachner, Jennifer Botha-Brink,  Torsten M. Scheyer, Markus Lambertz, G. S. Bever, Bruce S. Rubidge & Kevin de Queiroz. 2014. Origin of the Unique Ventilatory Apparatus of Turtles. Nature Communications. 5, Article number: 5211
doi: dx.doi.org/10.1038/ncomms6211

 facebook.com/233680374671/photos/10152894600519672

[PaleoTestudology • 2014] Eodortoka morellana • the first pan-pleurodiran turtle (Dortokidae) defined in the Early Cretaceous of Europe

Eodortoka morellana

Illustration by Carlos De Miguel Chaves

Highlights

• A new turtle taxa, Eodortoka morellana gen. et sp. nov. is proposed here.

• The new taxon comes from the Aptian of the Spanish Arcillas de Morella Formation.

• It is the only nominated dortokid prior to the uppermost Cretaceous.

• It shows several primitive characters not shared with the so far described dortokids.

Abstract

Dortokidae is a relatively poorly-known clade of Pan-Pleurodira, exclusively recognized in Europe. It is the only clade of Laurasiatic pan-pleurodirans known in the post-Jurassic record. Its presence has been recognized in several locations and ages. However, only two nominated valid taxa have been described so far: the western European Upper Cretaceous Dortoka vasconica, and the Romanian late Paleocene Ronella botanica. A new dortokid is studied here, Eodortoka morellana gen. et sp. nov. This new taxon is the oldest nominated dortokid, coming from the lower Aptian (Lower Cretaceous) of the Spanish town of Morella. It shows several primitive characters not shared with the so far described dortokids, such as the presence of mesoplastra and the absence of overlap of the second pair of pleural scutes onto the first pair of costal plates. The comparison of Eodortoka morellana gen. et sp. nov. with other specimens allows us to recognize the presence of two members of Dortokidae in the Iberian Lower Cretaceous record. This study shed light on the early evolution of Dortokidae, as well as on the systematic and paleobiogeography of this clade.

Keywords: Pan-Pleurodira; Dortokidae; Early Cretaceous; Europe; Morella

New mesozoic turtle Eodortoka morellana found in Morella, Castelló, Maestrazgo Basin, Iberian Range, Spain. 

Illustration by Carlos De Miguel Chaves

Systematic paleontology

Testudinata Klein [in Behn], 1760
Testudines Treviranus, 1802
Pan-Pleurodira Joyce, Parham and Gauthier, 2004

Dortokidae Lapparent de Broin and Murelaga, 1996
Eodortoka morellana, gen. et sp. nov.

Etymology. The generic name is composed by the terms Eo-, Greek for dawn, representing the oldest named genus of Dortokidae; and -dortoka, basque for turtle, the name of the type genus of this clade. The specific name refers to Morella, the town where the Mas de la Parreta quarry is located.

Referencia: Pérez-García, A.; Gasulla, J.M.; Ortega, F. 2014. Eodortoka morellana gen. et sp. nov., the first pan-pleurodiran turtle (Dortokidae) defined in the Early Cretaceous of Europe. Cretaceous Research. 48;130–138. DOI: dx.doi.org/10.1016/j.cretres.2013.12.004

http://godzillin.blogspot.com.es/2014/01/un-nueva-tortuga-mesozoica-en-morella.html

http://scientificillustration.tumblr.com/post/76509996959/paleoillustration-new-mesozoic-turtle-eodortoka

[Testudology • 2010] Distribution of the Big-Headed Turtle (Platysternon megacephalum, Gray 1831) in Thailand | การแพร่กระจายของเต่าปูลูในประเทศไทย

The different color morphologies of the carapaces of adult big-headed turtles;
(A1) brown, (B1) reddish-brown, (C1) olive, (D1) yellowish-brown and (E1) the new morph, dark gray; all with a squared-off front and rounded back end. The plastrons are usually (A2, D2) yellow, (B2) brownish, (C2) olive with yellowish and (E2) the new dark gray morph.
These specimens are from (A) the Mae Samard Watershed Management Unit, Mae Hong Son Province in the Salawin river basin, (B) the Umphang Wildlife Sanctuary, Tak Province in the Mae Klong river Basin, (C) the Tad Mok National Park, Phetchabun Province in the Pasak river basin, (D) the Pha Daeng National Park, Chiang Mai Province in the Kok river basin and (E) the Phu Suan Sai National Park, Loei Province in the Khong river basin.

The distribution of the big-headed turtle Platysternon megacephalum, Gray 1831 in Thailand was studied from Dec. 2006 to Apr. 2009.  Mountain streams of protected and unprotected areas throughout Thailand, except in the southern peninsular region, were ground surveyed.  This study confirms the occurrence of P. megacephalum in 1 new and 9 previously reported river basins in the northeastern part of Thailand.  Among these, 22 new localities at elevations of 430-1350 m were reported.  Most P. megacephalum individuals were found at night in small, often rapidly flowing mountain streams in dry dipterocarp and montane rainforests.  The water temperature of these streams ranged 15.5-20.3°C (X = 19.04 ± 2.10°C, n = 33), pH values ranged 5.32-8.07, and water depths were 14.0-95.0 cm (X = 41.67 ± 25.30 cm, n = 33).  The turtles appeared to be most abundant at elevations of 630-720 m. Platysternon megacephalum populations face serious threats from habitat loss, human consumption, and commercial harvest of turtles.  This species urgently needs an aggressive conservation program to ensure its survival. 

Key words: Platysternon megacephalum, big-headed turtle, distribution, Thailand.

Kruewan Pipatsawasdikul, Harold K. Voris, and Kumthorn Thirakhupt. 2010. Distribution of the Big-Headed Turtle (Platysternon megacephalum, Gray 1831) in Thailand. Zoological Studies. 49(5): 640-650. http://zoolstud.sinica.edu.tw/Journals/49.5/640.pdf

[PaleoTestudology • 2013] Kappachelys okurai • a new stem soft-shelled turtle from the Early Cretaceous of Japan

Abstract 

Kappachelys okurai gen. et sp. nov. is named and described based on two isolated carapacial elements (right seventh costal and left seventh peripheral) from the Lower Cretaceous (?upper Neocomian) Akaiwa Formation of west-central Honshu, Japan. Kappachelys is a small turtle (shell length ~10 cm) that exhibits a unique combination of three features: coarse and deep vermiculate sculpture on carpace; no scute sulci; and well-developed peripherals. The form of the sculpture and lack of scute sulci both suggest affinities with the Trionychidae (soft-shelled turtles), whereas the plesiomorphic retention of well-developed peripherals indicates Kappachelys lies outside the Trionychidae. Given this combination of primitive and derived features, we interpret Kappechelys as a stem trionychid. In the same region of Japan, the overlying Lower Cretaceous (Aptian) Kitadani Formation contains some of the oldest known, unequivocal trionychid fossils. Based on its slightly older age, similar geographical distribution, and more primitive shell morphology, Kappachelys could be ancestral to the trionychids of the Kitadani Formation.

Art: http://www.studio-corvo.com/blog/karasu/archives/2011/07/post_861.html

Ren Hirayama, Shinji Isaji and Tsuyoshi Hibino 2013. Kappachelys okurai gen. et sp. nov., a new stem soft-shelled turtle from the Early Cretaceous of Japan. In Donald B. Brinkman, Patricia A. Holroyd and James D. Gardner (eds). Morphology and Evolution of Turtles. Springer. pp. 179–185. doi:10.1007/978-94-007-4309-0_12

http://news.mynavi.jp/news/2011/08/05/055/index.html

http://www.waseda.jp/jp/news11/110805_suppon.html

http://www.city.hakusan.ishikawa.jp/kyouiku/hakusanrokubunsitukyouiku/shiramine-kyoiku/kaseki/sinnsyukaseki_8.jsp

[Testudology • 2012] Observations on the feeding ecology of Indotestudo elongata (Blyth, 1853) in the wild in Cambodia and Vietnam

Observations on the feeding ecology of Indotestudo elongata (Blyth, 1853) in the wild in Cambodia and Vietnam

Kulen Promtep Wildlife Sanctuary in the Northern Plains of Cambodia

During the study in Kulen Promtep Wildlife Sanctuary, three of the ten tagged tortoises were observed several times to feed on live Quantula striata, a land snail species deciduous forests in Indochina and peninsular Malaysia. Another individual was observed once feeding on a heavily decomposed skull of Viverra cf. zibetha (Fig. 4).

Cat Tien National Park in Dong Nai Province, southern Vietnam

The scat from Cat Tien consisted of the remains of two Ricefield Crabs Somanniathelphusa spp. At the beginning of the wet season these crabs are abundant around the seasonal ponds and on the forest floor (Ng, 1988). It is unknown if the tortoises consume these crabs for their proteins or also as a source of calcium. From the remains of the crab it was also impossible to ascertain whether the crab in fact was captured or, most probable, merely the carcass was consumed. 

Thus, our observations suggest that food items consumed by I. elongata vary according to their seasonal availability.

Figure 1. Indotestudo elongata feeding on the snail species Quantula striata in the Kulen Promtep Wildlife Sanctuary in northern Cambodia. Photo: F.Ihlow.

Figure 4. Indotestudo elongata feeding on a skull of Viverra cf. zibetha in the Kulen Promtep Wildlife Sanctuary in northern Cambodia. Photo: F. Ihlow.

Flora Ihlow, Peter Geissler, Sothanin Sovath, Markus Handschuh and Wolfgang Böhme. 2012. Observations on the feeding ecology of Indotestudo elongata (Blyth, 1853) in the wild in Cambodia and Vietnam. Herpetology Notes. 5. 5-7. 

http://www.herpetologynotes.seh-herpetology.org/contents5.html

http://www.herpetologynotes.seh-herpetology.org/Volume5_PDFs/Ihlow_et_al_Herpetology_Notes_Volume5_pages005-007.pdf

[Testudology • 2004] Malayemys macrocephala & M. subtrijuga | Geographic variation and systematics in the south-east Asian turtles of the genus Malayemys (Testudines: Bataguridae)

Malayemys macrocephala (Gray, 1859) from the Chao Phraya and Mae Klong river basins, coastal areas of south-eastern Thailand, and the Malay Peninsula

Malayemys subtrijuga (Schlegel and Müller, 1844)  from the Mekong River Basin

Geographic variation was studied in the south-east Asian turtles of the genus Malayemys (Testudines: Bataguridae). Discriminant function analysis of head-stripe and shell characters reveals a clear pattern of geographic variation that is consistent with the topography of south-east Asia and the poor dispersal abilities of these turtles. Two phenotypically and morphologically distinct groups of Malayemys occur allopatrically in lowland areas of mainland south-east Asia, and my data concludes that each should be recognized as a distinct species. Turtles from the Mekong River Basin retain the name Malayemys subtrijuga (Schlegel and Müller, 1844), whereas those from the Chao Phraya and Mae Klong river basins, coastal areas of south-eastern Thailand, and the Malay Peninsula are assigned the name Malayemys macrocephala (Gray, 1859).  Malayemys macrocephala has four or fewer nasal stripes (99%) and an infraorbital stripe that is relatively wide at the loreal seam (98% of InfSW/HW=0.07-0.18) and does not extend or extends only slightly superior to the loreal seam (96%). Conversely, M. subtrijuga has six or more nasal stripes (89%) and an infraorbital stripe that is relatively narrow at the loreal seam (92% of InfSW/HW=0.02-0.06), extends completely superior to the loreal seam (96%), and usually joins the supraorbital stripe (64%). Female M. macrocephala also have relatively longer AnL and relatively shorter Vert5L and PecL than M. subtrijuga. Similarly, male M. macrocephala have relatively longer PPLL and AbdL, relatively shorter Pleu1L and PecL, and greater RLatK values than M. subtrijuga. Both species are potentially threatened by overcollection and habitat destruction, and should be protected as separate taxa of concern. In addition, discriminant function analysis of shell and head-stripe characters suggests that M. subtrijuga on Java are derived by human intervention primarily from the Mekong River Basin.

Keywords: Testudines, systematics, Mekong, Chao Phraya, Mae Klong, Malayemys subtrijuga, Malayemys macrocephala.

Brophy, T. R. 2004. Geographic variation and systematics in the south-east Asian turtles of the genus Malayemys (Testudines: Bataguridae). Hamadryad. 29:63-79. 

http://digitalcommons.liberty.edu/cgi/viewcontent.cgi?article=1057&context=bio_chem_fac_pubs

[Testudology • 2011] Interspecific hybridization between Mauremys reevesii and Mauremys sinensis: Evidence from morphology and DNA sequence data

Figure 1. Specimen images of the three suspected hybrids (Hy1, Hy2, Hy3) and the putative parental species (pp1: Mauremys sinensis; pp2: Mauremys reevesii) 

Turtle hybrids have been found in some taxa, but so far, studies on interspecific hybridization between Mauremy reevesii and  Mauremy sinensis have not been reported. Recently, we obtained three specimens (Hy1, Hy2, Hy3) with unusual morphological characteristics from pet trade Market, which are suspected to be hybrids rather than new species, because they were morphologies intermediate between M. reevesii and  M. sinensis. In further study, we analyzed two aspects; morphological characteristics and molecular data, separately. The morphological characteristics showed that the pattern of the carapace, the plastron and neck stripes of the three specimens was between that of M. reevesii and M. sinensis (the morphological features of Hy1 and Hy2 have more resemblance with those of  M. sinensis, and those of Hy3 have more resemblance with those of M. reevesii). In molecular analyses, two mitochondrial genes (12S, cytb) and two nuclear genes (RAG-1, R35) were respectively cloned from each suspected specimen. One sequence was obtained for each mitochondrial gene, while two different sequences were obtained for each nuclear gene. Phylogenetic analyses revealed that mitochondrial genes sequences from each suspected specimen clustered into the corresponding sequences of their putative female parents, while the two pairs nuclear parental alleles sequences were strongly paraphyletic, for they were included in two different genetic lineages (M. reevesii and  M. sinensis). Therefore, we concluded that the three suspected specimens are hybrids (Hy1 and Hy2:  M. reevesii ♂ ×  M. sinensis ♀ ; Hy3: M. sinensis ♂ ×  M. reevesii ♀). It is the first report that interspecies hybridization of M. reevesii and M. sinensis can cross completely. 

Key words: Mauremys reevesii, Mauremys sinensis, hybridization, morphology, DNA sequence.  

Xingquan Xia, Ling Wang, Liuwang Nie, Zhengfeng Huang, Yuan Jiang, Wanxing Jing and 

Luo Liu. 2011. Interspecific hybridization between Mauremys reevesii and Mauremys sinensis: Evidence from morphology and DNA sequence data. African Journal of Biotechnology. 10(35), 6716-6724. 

http://www.academicjournals.org/ajb/PDF/pdf2011/13Jul/Xia%20et%20al.pdf

[Testudology • 2005] On the hybridisation between two distantly related Asian turtles (Testudines: Sacalia × Mauremys)

Fig. 1. Sacalia quadriocellata × Mauremys reevesii hybrids. A) Living specimen in the care of JFP showing head coloration including detail of “eye spots” and malar region; B) same specimen in ventral view; C) The specimen sequenced in this study (MVZ 241502) in ventral view.

Abstract

This is the first report of a hybridisation between Sacalia and Mauremys (Bataguridae). New data and a review of the literature show that 19 batagurid hybridisations are documented. Many more undoubtedly exist, but have not been documented and reported. Most hybrids are members of the Cuora + Mauremys clade and 17 of 19 reported hybrids have at least one member from this clade. The Sacalia × Mauremys hybridisation reported here is only the third hybridisation between a species of the Cuora + Mauremys clade and a species outside of that clade.

Key words. Bataguridae: Mauremys, Sacalia; hybrids.

Buskirk, James R.; Parham, James F. & Feldman, Chris R. 2005. On the hybridisation between two distantly related Asian turtles (Testudines: Sacalia × Mauremys). Salamandra. 41: 21-26.

http://wolfweb.unr.edu/~ophis/Feldman_Lab/Publications_files/Buskirk%2605-SAL.pdf

[Testudology • 2004] An Ocadia sinensis x Cyclemys shanensis hybrid (Testudines: Geoemydidae)

Fig: The captive bred Ocadia sinensis x Cyclemys shanensis hybrid, September 2003 (11 months old). The roofed, distinctly tricarinate shell and the serrated posterior marginals resemble Cyclemys spp. The neck and facial stripes as well as the plastral pattern are similar to O. sinensis. The plastral pattern was more contrasting as a hatchling and has faded during growth. Photos: F. Höhler.

Abstract

A captive bred Ocadia sinensis x Cyclemys shanensis hybrid is described. Its hybrid status was confirmed by a comparison of a 1036 bp fragment of the mitochondrial cytochrome b gene with the putative mother (C. shanensis) and genomic ISSR fingerprinting. This is the first report of an intergeneric hybrid between very distantly related geoemydid turtles. All previous geoemydid intergeneric hybrids have been crossings within or between two sister clades containing the currently accepted genera (Chinemys, Mauremys, Ocadia) and (Cuora, Pyxidea).

Key words: Cyclemys, Ocadia, testudines, intergeneric hybrid.

Schilde, Maik, Dana Barth and Uwe Fritz 2004. An Ocadia sinensis x Cyclemys shanensis hybrid (Testudines: Geoemydidae). Asiatic Herpetological Research. 10: 120-125

http://www.asiatic-herpetological.org/Archive/Volume%2010/10_11.pdf