New material and a reassessment of soft-shelled turtles (Trionychidae) from the Late Cretaceous of Middle Asia and Kazakhstan

Vitek, Natasha; Danilov, Igor G.

doi:10.1080/02724631003617548

Cited by 32 publications

(51 citation statements)

References 9 publications

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“…kyrgyzensis. In general, this pattern is similar to those of "Trionyx" kansaiensis (see Vitek and Danilov, 2010).…”

Section: Systematic Paleontologysupporting

confidence: 58%

“…In smaller specimens, the ridges surrounding the pits are thinner and more pronounced, similar to the sculpturing seen in "T." kyrgyzensis Nessov, 1995. In general, this sculpturing is more similar to that of Aspideretoides riabinini (Kuznetsov and Chkhikvadze, 1987), than to that of "Trionyx" kansaiensis Danilov, 2010 (see Vitek andDanilov, 2010;Danilov et al, in press).…”

Section: Systematic Paleontologymentioning

confidence: 98%

“…It is unclear whether or not this species was sexually dimorphic. Sculpturing A e Dzharakuduk; B e Baybishe; C e Shakh Shakh; D e Kyrkkuduk I; E e Kansai; F e Kylodzhun; G e localities of the Khodzhakul Formation (see Vitek and Danilov (2010 and Danilov and Vitek (2013) for data on localities other than localities of the Khodzhakul Formation and Itemir).…”

Section: Systematic Paleontologymentioning

confidence: 99%

“…This paper continues a series of publications on Cretaceous trionychids of Asia (Danilov and Vitek, 2009;Vitek and Danilov, 2010Danilov andVitek, 2012, 2013) and is devoted to trionychids from the early Late Cretaceous (Cenomanian) of Uzbekistan, situated in the region called Middle Asia and Kazakhstan ( Fig. 1; see Vitek and Danilov [2010] for more details about the geography of Middle Asia and Kazakhstan).…”

Section: Introductionmentioning

confidence: 99%

“…1; see Vitek and Danilov [2010] for more details about the geography of Middle Asia and Kazakhstan). The material described in this paper comes from localities in the early Cenomanian Khodzhakul Formation of the southwestern Kizylkum Desert area, Karakalpakistan, and from the Cenomanian of the Itemir locality in the central Kizylkum Desert, Navoi Viloyat (district) (Fig.…”

Section: Introductionmentioning

confidence: 99%

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Soft-shelled turtles (Trionychidae) from the Cenomanian of Uzbekistan

Vitek

Danilov

2014

Cretaceous Research

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a b s t r a c tLocalities from the Cenomanian of Uzbekistan are the oldest in Middle Asia and Kazakhstan to preserve two broadly sympatric species of trionychid turtle. Material described here comes from multiple Cenomanian formations from the Itemir locality, and from multiple localities in the Cenomanian Khodzhakul Formation. The first taxon from the locality, "Trionyx" cf. kyrgyzensis, has multiple morphological similarities with the older, Early Cretaceous "Trionyx" kyrgyzensis. In contrast, the second taxon, "Trionyx" dissolutus, has multiple similarities with "Trionyx" kansaiensis, one of two species of trionychid found in younger Late Cretaceous localities. "Trionyx" dissolutus bears some superficial resemblance to other trionychid taxa within the clade Plastomenidae because of its highly ossified plastron with a hyoplastral lappet and an epiplastral notch. However, Plastomenidae is diagnosed primarily through characters that are absent or cannot be observed in the available material of "T." dissolutus, and other shared features are plesiomorphic. In addition, "T." dissolutus shares other synapomorphies with Trionychinae. A heavily ossified plastron may be more homoplastric within Trionychidae than has been previously recognized. Finally, we provide an improved understanding of the subtle similarities and differences between several closely related Cretaceous turtle assemblages of Middle Asia and Kazakhstan.

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“…kyrgyzensis. In general, this pattern is similar to those of "Trionyx" kansaiensis (see Vitek and Danilov, 2010).…”

Section: Systematic Paleontologysupporting

confidence: 58%

Section: Systematic Paleontologymentioning

confidence: 98%

Section: Systematic Paleontologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Soft-shelled turtles (Trionychidae) from the Cenomanian of Uzbekistan

Vitek

Danilov

2014

Cretaceous Research

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Quantifying shell patterning helps identify species of Trionychidae

Pamfilie

Espinal

Vitek

2022

The Anatomical Record

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Softshell turtles (Trionychidae) display characteristic pits and ridges, or "sculpturing," on the bony carapace. Variation in sculpturing pattern may be useful in classifying fossilized shell fragments. Although past attempts could discern qualitative differences in certain best-case scenarios, many early taxonomic uses of sculpturing traits have been reevaluated as unreliable in the face of intraspecific variation. The potential of sculpturing to contain consistently reliable, quantitative, taxonomically informative traits remains underexplored. Here, we revisit this idea by quantifying trionychid shell patterning with topographic measurement techniques more commonly applied to nonhomologous quantification of mammalian teeth and geographic surface topography. We assess potential sources of variation and accuracy of these metrics for species identification. Carapaces of extant specimens used in this study included members of the species Apalone ferox, Apalone spinifera, and Amyda cartilaginea and were obtained from the herpetology collections of the Florida Museum of Natural History. 3D scans of shells were systematically sampled to create digital "fragments." These fragments were quantified using three topographic measurements: Dirichlet Normal Energy (DNE), Relief Index (RFI), and Orientation Patch Count Rotated (OPCR). A nested MANOVA suggests there is significant variation at the species, individual, and carapace location levels of analysis. Linear discriminant analysis correctly predicts a sample's species identity from DNE, RFI, and OPCR 75.2% of the time. These promising results indicate that topographic measures may provide a method for identifying shell fragments that are currently identifiable only as Trionychidae indet. Future work should explore this approach in additional species and account for ontogenetic changes.

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