Chondrocranium and skeletal development of <i>Phrynops hilarii</i> (Pleurodira: Chelidae)

Bona, Paula; Alcalde, Leandro

doi:10.1111/j.1463-6395.2008.00356.x

Cited by 27 publications

(68 citation statements)

References 44 publications

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“…In spite of this and the early description of the adult anatomy of Pelodiscus by Ogushi (1911) and of several aspects of shell development by Cherepanov (1995), there are no data on skeletal formation in this species. Sheil (2003) described skeletal development in the trionychid Apalone spinifera, and there are similar works on other cryptodires (Chelydra serpentina: Rieppel, 1993a;Sheil and Greenbaum, 2005; Macrochelys temminckii : Sheil, 2005; Trachemys scripta: Sheil and Portik, 2008), and the pleurodire Phrynops hilarii (Bona and Alcalde, 2009). Here, we provide a summary of developmental events with focus on those stages that are most informative for the onset and early ossification of skeletal elements.…”

Section: Introductionmentioning

confidence: 86%

Skeletal development in the Chinese soft‐shelled turtle Pelodiscus sinensis (Testudines: Trionychidae)

Sánchez‐Villagra

Müller

Sheil

et al. 2009

Journal of Morphology

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We investigated the development of the whole skeleton of the soft-shelled turtle Pelodiscus sinensis, with particular emphasis on the pattern and sequence of ossification. Ossification starts at late Tokita-Kuratani stage (TK) 18 with the maxilla, followed by the dentary and prefrontal. The quadrate is the first endoskeletal ossification and appears at TK stage 22. All adult skull elements have started ossification by TK stage 25. Plastral bones are the first postcranial bones to ossify, whereas the nuchal is the first carapacial bone to ossify, appearing as two unstained anlagen. Extensive examination of ossification sequences among autopodial elements reveals much intraspecific variation. Patterns of ossification of cranial dermal elements are more variable than those of endochondral elements, and dermal elements ossify before endochondral ones. Differences in ossification sequences with Apalone spinifera include: in Pelodiscus sinensis the jugal develops relatively early and before the frontal, whereas it appears later in A. spinifera; the frontal appears shortly before the parietal in A. spinifera whereas in P. sinensis the parietal appears several stages before the frontal. Chelydrids exhibit an early development of the postorbital bone and the palatal elements as compared to trionychids. Integration of the onset of ossification data into an analysis of the sequence of skeletal ossification in cryptodirans using the event-pairing and Parsimov methods reveals heterochronies, some of which reflect the hypothesized phylogeny considered taxa. A functional interpretation of heterochronies is speculative. In the chondrocranium there is no contact between the nasal capsules and planum supraseptale via the sphenethmoid commissurae. The pattern of chondrification of forelimb and hind limb elements is consistent with a primary axis and digital arch. There is no evidence of anterior condensations distal to the radius and tibia. A pattern of quasi- simultaneity is seen in the chondrogenesis of the forelimb and the hind limb.

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Section: Introductionmentioning

confidence: 86%

Skeletal development in the Chinese soft‐shelled turtle Pelodiscus sinensis (Testudines: Trionychidae)

Sánchez‐Villagra

Müller

Sheil

et al. 2009

Journal of Morphology

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“…The presence or absence of each of the elements of the skeleton indicated the ontogenetic sequence. We then compared data for P. unifilis with other taxa cited in the literature, such as other Pleurodira ( P. expansa [Vieira et al, 2009]); ( Emydura subglobosa, Pelusios sinuatus, Pelomedusa subrufa [Scheyer et al, 2008]), ( Phrynops hilarii [Bona and Alcalde, 2009]), and Cryptodira ( Apalone spinifera [Sheil, 2003]); ( Chelydra serpentina [Rieppel, 1993; Sheil and Greenbaum, 2005]); ( Macrochelys temminckii [Sheil, 2005]); ( Trachemys scripta [Gilbert et al, 2001]); ( Pelodiscus sinensis [Sánchez‐Villagra et al, 2009]); and ( Trionyx sinensis [Cherepanov, 1995]). The summarized phylogeny of these Testudines is described in the cladogram below (Fig.…”

Section: Methodsmentioning

confidence: 99%

Ontogeny of the Shell Bones of Embryos of Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae)

Lima

Santos

Vieira

et al. 2011

The Anatomical Record

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The aim of the present study was to investigate the sequence of shell bone formation in the embryos of the Pleurodira, Podocnemis unifilis. Their bones and cartilage were collected and cleared before staining. The shell was also examined by obtaining a series of histological slices. All the bony elements of the plastron have independent ossification centers, which subsequently join together and retain two fontanelles until the period of hatching. This turtle has a mesoplastra, which is characteristic of the Podocnemididae. The carapace begins to form concurrently with the ossification of the ribs at the beginning of stage 20. All the plates, except the suprapygal, initiate ossification during the embryonic period. The main purpose of the histological investigation was to highlight the relationship between the formation of the carapace and ribs with that of the neural plates. The costal and neural plates were found not to independent ossification centers, but to be closely related to components of the endoskeleton, originating as expansions of the perichondral collar of the ribs

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“…The large body of recent literature pertaining to the development of extant turtles placed much effort into densely sampling ontogenetic stages to clarify sequences of chondrification and ossification (Rieppel, 1993a;Sheil, 2003aSheil, ,b, 2005Sheil & Greenbaum, 2005;S anchez-Villagra et al 2007aS anchez-Villagra et al ,b, 2008Sheil & Portik, 2008;Bona & Alcalde, 2009;Vieira et al 2011). Although much variation is apparent, all available developmental data from recent turtles agree in that the hooked element ossifies after metatarsals I-IV, but prior to all tarsals.…”

Section: Timing Of Developmentmentioning

confidence: 99%

The hooked element in the pes of turtles (Testudines): a global approach to exploring primary and secondary homology

2013

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The hooked element in the pes of turtles was historically identified by most palaeontologists and embryologists as a modified fifth metatarsal, and often used as evidence to unite turtles with other reptiles with a hooked element. Some recent embryological studies, however, revealed that this element might represent an enlarged fifth distal tarsal. We herein provide extensive new myological and developmental observations on the hooked element of turtles, and re-evaluate its primary and secondary homology using all available lines of evidence. Digital count and timing of development are uninformative. However, extensive myological, embryological and topological data are consistent with the hypothesis that the hooked element of turtles represents a fusion of the fifth distal tarsal with the fifth metatarsal, but that the fifth distal tarsal dominates the hooked element in pleurodiran turtles, whereas the fifth metatarsal dominates the hooked element of cryptodiran turtles. The term 'ansulate bone' is proposed to refer to hooked elements that result from the fusion of these two bones. The available phylogenetic and fossil data are currently insufficient to clarify the secondary homology of hooked elements within Reptilia.

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Chondrocranium and skeletal development of Phrynops hilarii (Pleurodira: Chelidae)

Cited by 27 publications

References 44 publications

Skeletal development in the Chinese soft‐shelled turtle Pelodiscus sinensis (Testudines: Trionychidae)

Skeletal development in the Chinese soft‐shelled turtle Pelodiscus sinensis (Testudines: Trionychidae)

Ontogeny of the Shell Bones of Embryos of Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae)

The hooked element in the pes of turtles (Testudines): a global approach to exploring primary and secondary homology

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