Growth and life history of freshwater chelydrid turtles (Testudines: Cryptodira): A bone histological approach Mohd Shafi Bhat, Thomas M. Cullen Journal of Anatomy, 2025 The current study examines the growth pattern and lifestyle habits of the freshwater snapping turtles Chelydra and Macrochelys based on limb bone histology. Femora, humeri, and tibiae of 25 individuals selected from a range of ontogenetic stages were assessed to determine inter‐element and intraskeletal histological variation. Osteohistological assessment of multiple elements is consistent with overall moderate growth rates as revealed by the dominance of parallel‐fibered bone. However, the growth was cyclical as shown by deposition of multiple lines of arrested growths in the compacta. It appears that the bone tissue of C. serpentina is more variable through ontogeny with intermittent higher growth rates. M. temminckii appears to grow more slowly than C. serpentina possessing compact and thick cortices in accordance with their larger size. Overall, vascularization decreases through ontogeny with humeri and femora being well‐vascularized in both species. Contrarily, epipodials are poorly vascularized, though simple longitudinal and radial canals are present, suggesting differences in growth patterns when compared with associated diaphyseal sections. The tibiae were found to be the least remodeled of the limb bones and therefore better suited for skeletochronology for snapping turtles. Intra‐elementally, femora and humeri preserved higher cortical vascularity ventrally, suggestive of faster relative growth. We hypothesize that the differential growth pattern in limb bones of snapping turtles may relate to differential functional constraints, where forelimbs are operational in swimming while the hindlimbs provide stability.
Bone histology of Neogene angulate tortoises (Testudines: Testudinidae) from South Africa: palaeobiological and skeletochronological implications Mohd Shafi Bhat, Anusuya Chinsamy, John Parkington Royal Society Open Science, 2023 Here we examine the tibial microstructure of modern and fossil angulate tortoises to assess the histology and growth from the late Miocene–early Pliocene, Pleistocene through to modern forms. The cross-sections of all the tibiae sampled revealed highly vascularized, uninterrupted, fibrolamellar bone tissue during early ontogeny, which suggests that early growth was fast. However, later in ontogeny, growth was slower, as indicated by the deposition of parallel-fibred bone tissue in the outer cortex, and even ceased periodically, as indicated by lines of arrested growth. Comparative analyses of the growth rates of the tortoises from different time periods showed that the tortoises from the late Miocene–early Pliocene Langebaanweg locality and from Diepkloof Rock Shelter had relatively slower growth rates under less optimal growth conditions. Additionally, these prehistoric specimens show extensive remodelling, and several generations of secondary osteons further suggest functional and/or metabolic stresses on the skeleton. Palaeoenvironmental reconstructions suggest that it was mostly cooler and drier with seasonal fluctuations in late Miocene–early Pliocene, and it is likely that Chersina responded to these conditions by having a lower rate of growth as compared with their modern counterparts, which thrive in the current prevailing more favourable Mediterranean type of climate.
A new clevosaurid (Lepidosauria: Rhynchocephalia) from the Upper Triassic of India Mohd Shafi Bhat, Debajit Datta, Sanghamitra Ray, P. M. Datta Journal of Vertebrate Paleontology, 2023 A new clevosaurid rhynchocephalian is described from the Upper Triassic Tiki Formation of the Rewa Gondwana Basin of India. The material is based on several partial craniomandibular elements containing acrodont and fully ankylosed tooth implantations and on the basis of multiple diagnostic features is assigned to a new taxon, Clevosaurus nicholasi. Phylogenetic analysis nests the Tiki rhynchocephalian within the clade Clevosauridae, where it is recovered as an early-diverging taxon basal to the other clevosaurs except for a clade comprising C. convallis + Sigmala sigmala. The autapomorphic characters of Clevosaurus nicholasi include a very robust dentary with an obliquely angled narrow lip of the secondary bone at the symphysis, anteriorly bifurcated Meckelian canal, a sub-dental shelf on the dentary, acrodont marginal anterior teeth, and absence of or smooth lateral and medial wear facets on the marginal dentary and maxillary teeth, respectively. The Late Triassic rhynchocephalian record of the Gondwana is relatively sparse in comparison with that of the Laurasian regions, and the new clevosaur represents the first Late Triassic record from India. Based on the paleobiogeographic distribution, a possible Gondwanan origin for Clevosauridae is hypothesized.
Bone histology of dinocephalians (Therapsida, Dinocephalia): palaeobiological and palaeoecological inferences Mohd Shafi Bhat, Christen D. Shelton, Anusuya Chinsamy Papers in Palaeontology, 2022 Abstract We investigate the bone histology of multiple skeletal elements of dinocephalian taxa from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. The results show that the cortex is predominantly composed of fibrolamellar bone, suggesting rapid osteogenesis for these basal non‐mammalian therapsids. However, in a few skeletal elements, growth marks interrupt the deposition of the fibrolamellar bone tissue, indicating periodic arrests in growth. Ontogenetic differences are observed among the specimens studied: the majority have fibrolamellar bone deposited up to the peripheral margin of the bone wall, indicating continuous fast growth right up to the time of death, while a few specimens have avascular lamellar bone tissue with multiple, closely spaced rest lines, indicating maturity and a slowing down of growth prior to death. Several taxon‐specific histological variations in terms of orientation of vascular canals and primary osteons, incidence of growth marks, and extent of secondary medullary reconstruction suggest slight differences in growth trajectories between the different taxa. The skeletal elements of the herbivorous taxa ( Keratocephalus , Moschops and Struthiocephalus ) and the omnivorous Jonkeria , previously studied, are characterized by a thick cortex, and extensively developed medullary spongiosa, suggestive of semi‐aquatic habits. In contrast, the femoral histology of the carnivorous Anteosaurus suggests that it was more terrestrial.
Inter-element variation in the bone histology of Anteosaurus (Dinocephalia, Anteosauridae) from the Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa Mohd Shafi Bhat, Christen D. Shelton, Anusuya Chinsamy Peerj, 2021 Despite its abundance in the Permian fossil record of South Africa, little is known about the life history of Anteosaurus. Here we examine the bone microstructure of multiple skeletal elements of Anteosaurus from the Tapinocephalus Assemblage Zone of the Karoo Basin. The bone histology of Anteosaurus magnificus reveals that the cortex is composed of highly vascularized, uninterrupted fibrolamellar bone tissue surrounding the inner spongy medullary region. However, the histology of two ribs and a previously described femur of another Anteosaurus taxon revealed an interrupted growth pattern with lines of arrested growth and peripheral rest lines occurring in the compacta, indicating periodic pauses in growth possibly linked to the slowing down of growth during maturity. Given that the fibula of the same individual has well-vascularised fibrolamellar bone tissue without any growth marks in the cortex; this suggests variation in skeletal growth. Based on our histological results, three growth dynamic stages are deduced for the genus Anteosaurus: (i) the earliest growth stage is represented by the predominance of highly vascularized, uninterrupted fibrolamellar bone tissue in the inner cortex, which suggests rapid periosteal bone deposition during early ontogeny; (ii) the next stage of growth shows periodic interruptions in the bone deposition as indicated by the deposition of lines of arrested growth; (iii) the third stage shows the development of lamellar bone tissue with rest lines in the peripheral part of the cortex suggesting a slowing down of growth prior to death. Most of the skeletal elements are characterized by thick bone walls, extensive secondary reconstruction and the complete infilling of the medullary cavity. However, the radius and a previously studied femur have open medullary cavities with struts of bony trabeculae. Based on histologic structures and comparisons with extant taxa, it is likely that Anteosaurus may have been more terrestrial as its osteology point towards terrestriality, but it may have occasionally inhabited ephemeral pools like modern semi-aquatic Hippopotamus.
Histological investigation of burnt bones: A case study of angulate tortoises from the archaeological site, Diepkloof Rock Shelter, Western Cape, South Africa Mohd Shafi Bhat, Anusuya Chinsamy, John Parkington International Journal of Osteoarchaeology, 2021 Abstract The current study examined burnt and unburnt tibiae of angulate tortoises from the intermediate and late Howiesons Poort levels at Diepkloof Rock Shelter (DRS) of Western Cape, South Africa, to ascertain heat‐induced osteohistological changes. Three types of bone damage caused by fire were recognized: (a) external color change in the bones but otherwise consistent osteological and histological features to unburnt bones; (b) partially burned bones with osteological features obliterated, but histological details still preserved, and carbon inclusions visible along the bone margins and within pore spaces; and (c) completely burned bones with obliterated osteological features, but overall shape is maintained, and except for the presence of cracks and carbon accumulations within pore spaces and around the periosteal margin, histological features are evident. Comparisons with other studies of burnt bone suggest that the bones at DRS were subjected to high temperatures of about 600°C to 900°C. Despite exposure to fire, histological features were intact in all the bones, permitting life history deductions for these angulate tortoises. During early ontogeny, uninterrupted fibrolamellar bone tissue (indicative of rapid growth rates) was deposited, whereas later in ontogeny, slowly formed parallel‐fibered bone tissue formed and growth ceased periodically. A minimum age of 10 years was deduced for two individuals, and closely spaced growth marks suggest that the sexual maturity was attained at 7–8 years. Based on the comparisons with modern angulate tortoises, it appears that DRS tortoises had slower growth rates, suggesting less optimal environmental conditions for growth prevailed at the time.
New cynodonts (Therapsida, Eucynodontia) from the Late Triassic of India and their significances Mohd Shafi Bhat, Sanghamitra Ray, P. M. Datta Journal of Paleontology, 2021 The Upper Triassic Tiki Formation of India has yielded several new cynodont taxa, which are described on the basis of multiple isolated teeth and a jaw fragment. A new species of dromatheriid, Rewaconodon indicus, is defined by a tri- and tetracuspid asymmetric crown, long anterior edge of the major cusp a, cingular cusps d and f, and marked constriction at the crown-root junction. Another new dromatheriid, Inditherium floris n. gen. n. sp., is characterized by a broad, flower-shaped pentacuspid crown, multiple cingular cusps, and a weak lingual cingulum is also described from the same horizon. In addition, a new mammaliamorph taxon, Tikiodon cromptoni n. gen. n. sp., is established on a tooth specimen, which has a shovel-shaped crown, three closely spaced main cusps, a pronounced lingual cingulum with multiple cingular cusps, and a root of incomplete root bifurcation. Such a tooth morphology occupies an intermediate position between the non-mammalian cynodonts and the early mammals, as is evident from the co-occurrence of various cynodont dental morphotypes in the Tiki Formation. Moreover, Late Triassic cynodonts occurred along narrow belts demarcated by paleolatitudes, though the Indian fauna shows both Laurasian and Gondwanan affinities.UUID: http://zoobank.org/c2c575ad-ee23-4f33-8a30-661c548a5b17
Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa Mohd Shafi Bhat, Christen Shelton, Anusuya Chinsamy Acta Palaeontologica Polonica, 2021 Here we examine the bone histology of multiple skeletal elements of three individuals of Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. Our histological results reveal a predominance of highly vascularized, uninterrupted fibrolamellar bone tissue, which suggests rapid periosteal bone deposition and an overall fast growth. However, in a rib, the periosteal bone deposition periodically stops abruptly, resulting in the deposition of several lines of arrested growth. The absence of bone growth marks in the limb bones (except for an annulus in a radius) suggests a young ontogenetic status for all specimens of the studied sample. All the skeletal elements are characterized by thick bone walls, extensive secondary reconstruction and the complete infilling of the medullary cavity by bony trabeculae. The latter condition is different to observations of contemporaneous graviportal terrestrial pareiasaurs, but similar to the observations in the modern semi-aquatic Hippopotamus, and suggests a possible semi-aquatic lifestyle for Jonkeria. On the basis of our histological findings, we assert that during early ontogeny Jonkeria experienced rapid sustained rates of growth, whereas later in ontogeny they experienced cyclical rates of growth.
First record of varied archosauriforms from the Upper Triassic of India based on isolated teeth, and their biostratigraphic implications Sanghamitra Ray, Mohd Shafi Bhat, P. M. Datta Historical Biology, 2021 A new rich and varied assemblage of archosauriform teeth is reported from the Upper Triassic Tiki Formation of India. Twelve morphotypes are identified based on their distinctive morphology, crown proportions, nature of serrations/denticles and serration density. Morphotypes I and II show similarity with that of Galtonia and Protecovasaurus, respectively, whereas morphotypes III–VI have low, subtriangular or leaf-shaped, asymmetrical, labiolingually compressed crowns with lenticular-subcircular bases and are diagnosed as belonging to different indeterminate archosauriforms. Morphotype VII shows similarity with aetosaur teeth, whereas morphotypes VIII–XII are ziphodont teeth having high, cylindrical, recurved crown with labiolingual compression, serrated carinae and subrectangular serrations, and are theropod-like. Variation in dental histology is noted between these morphotypes based on extent of pulp cavity, dentinal tubules and von Ebner lines of incremental growth. In multivariate analyses, there is considerable overlapping of convex hull polygons with morphospaces of other known archosauriforms such as Protecovasaurus, Crosbysaurus and Tecovasaurus known from the lower Tecovas Formation of the Chinle Group, USA. Such similarity correlates the two horizons despite wide geographic separation, suggesting that the age of the Tiki Formation may be younger than that previously suggested. Based on the known fossil flora and fauna, a mid-late Carnian age is proposed for the Tiki Formation.
A record of new lungfishes (Osteichthyes: Dipnoi) from the Carnian (Upper Triassic) of India Mohd Shafi Bhat, Sanghamitra Ray Historical Biology, 2020 Numerous tooth plates of different types were recovered from the Upper Triassic Tiki Formation of India. Sharp crested tooth plates with five acute ridges, tubercles on the crests, robust and deep furrows, wide spaces between successive ridges and reticulate ornamentation on the occlusal surfaces are assigned to a new species of the dipnoan genus Ptychoceratodus. Another tooth plate, characterized by four ridges with conical and cusplet-like denticles is identified as a Gnathorhiza. This is the first record of gnathorhizid fishes from the Upper Triassic sediments around the world. The Tiki aquatic realm was inhabited by different types of fishes including freshwater sharks, omnivorous/carnivorous dipnoans and other bony fishes. Palaeobiogeographic distribution of the dipnoans suggests that these were restricted to a high palaeolatitude in the southern hemisphere, where co-occurrences of several genera are seen in India.
A late Cretaceous paleo fire record and its implications for fire regime evolution. C Welch, T Cullen, RS Vachula, MS Bhat, D Evans AGU25 , 2025 2025
Bone histology and life history of freshwater turtles (Testudines: Cryptodira) MS Bhat, TM Cullen Society of Vertebrate Paleontology Annual Meeting, 102 , 2024 2024
Growth and life history of freshwater chelydrid turtles (Testudines: Cryptodira): A bone histological approach MS Bhat, TM Cullen Journal of anatomy , 2024 2024 Citations: 4
Bone histology of Neogene angulate tortoises (Testudines: Testudinidae) from South Africa: palaeobiological and skeletochronological implications MS Bhat, A Chinsamy, J Parkington Royal Society Open Science 10 (3) , 2023 2023 Citations: 8
A new clevosaurid (Lepidosauria: Rhynchocephalia) from the Upper Triassic of India MS Bhat, D Datta, S Ray, PM Datta Journal of Vertebrate Paleontology 43 (1), e2232833 , 2023 2023 Citations: 4
Bone histology of dinocephalians (Therapsida, Dinocephalia): palaeobiological and palaeoecological inferences MS Bhat, CD Shelton, A Chinsamy Papers in Palaeontology 8 (1), e1411 , 2022 2022 Citations: 11
Inter-element variation in the bone histology of Anteosaurus (Dinocephalia, Anteosauridae) from the Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa MS Bhat, CD Shelton, A Chinsamy PeerJ 9, e12082 , 2021 2021 Citations: 2
Histological investigation of burnt bones: a case study of angulate tortoises from the archaeological site, Diepkloof Rock Shelter, Western Cape, South Africa MS Bhat, A Chinsamy, J Parkington International Journal of Osteoarchaeology, https://doi.org/10.1002/oa.2986 , 2021 2021 Citations: 7
First record of varied archosauriforms from the Upper Triassic of India based on isolated teeth, and their biostratigraphic implications S Ray, MS Bhat, PM Datta Historical Biology 33 (2), 237-253 , 2021 2021 Citations: 15
Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa MS Bhat, CD Shelton, A Chinsamy Acta Palaeontologica Polonica 66 (4), 705-721 , 2021 2021 Citations: 5
Effect of fire on the bone histology of tortoise bones from a 45-65 ka old archaeological site from South Africa Mohd Shafi Bhat, Anusuya Chinsamy, John Parkington TaphCon, virtual meeting, Abstract Volume, p. 21 , 2020 2020
New cynodonts (Therapsida, Eucynodontia) from the Late Triassic of India and their significances MS Bhat, S Ray, PM Datta Journal of Paleontology, 1-18 , 2020 2020 Citations: 11
Long bone histology of Chersina angulata : Interelement variation and life history data MS Bhat, A Chinsamy, J Parkington Journal of Morphology 280 (12), 1881-1899 , 2019 2019 Citations: 30
First record of Mesozoic scroll coprolites: classification, characteristics, elemental composition and probable producers N Rakshit, MS Bhat, D Mukherjee, S Ray Palaeontology 62 (3), 451-471 , 2019 2019 Citations: 28
A record of new lungfishes (Osteichthyes: Dipnoi) from the Carnian (Upper Triassic) of India Bhat, M.S., and Ray, S. Historical Biology 32 (2, 2020), 428–437 , 2018 2018 Citations: 17
A new assemblage of freshwater sharks (Chondrichthyes: Elasmobranchii) from the Upper Triassic of India MS Bhat, S Ray, PM Datta Geobios 51 (4), 269-283 , 2018 2018 Citations: 27
A new assemblage of vertebrate microfossils from India: a window on Late Triassic biodiversity and palaeobiogeography MS Bhat IIT Kharagpur , 2018 2018 Citations: 8
A new hybodont shark (Chondrichthyes, Elasmobranchii) from the Upper Triassic Tiki Formation of India with remarks on its dental histology and biostratigraphy MS Bhat, S Ray, PM Datta Journal of Paleontology 92 (2), 221-239 , 2018 2018 Citations: 33
First report of dinosaurian claws from the Late Triassic of India Rakshit, N., Bhat, M. S., Ray, S., Datta, P. M. Palaeoworld 27 (2), 179–187 , 2018 2018 Citations: 17
Techniques for systematic collection and processing of vertebrate microfossils from their host mudrocks: A case study from the Upper Triassic Tiki Formation of India Bhat, M. S. Journal of the Geological Society of India 89 (4), 369-374 , 2017 2017 Citations: 12
MOST CITED SCHOLAR PUBLICATIONS
Vertebrate fauna from the Late Triassic Tiki Formation of India: new finds and their biostratigraphic implications. Ray, S., Bhat, M. S., Mukherjee, D., and Datta, P. M. Palaeobotanist 65, 47-59. , 2016 2016 Citations: 37
A new hybodont shark (Chondrichthyes, Elasmobranchii) from the Upper Triassic Tiki Formation of India with remarks on its dental histology and biostratigraphy MS Bhat, S Ray, PM Datta Journal of Paleontology 92 (2), 221-239 , 2018 2018 Citations: 33
Long bone histology of Chersina angulata : Interelement variation and life history data MS Bhat, A Chinsamy, J Parkington Journal of Morphology 280 (12), 1881-1899 , 2019 2019 Citations: 30
First record of Mesozoic scroll coprolites: classification, characteristics, elemental composition and probable producers N Rakshit, MS Bhat, D Mukherjee, S Ray Palaeontology 62 (3), 451-471 , 2019 2019 Citations: 28
A new assemblage of freshwater sharks (Chondrichthyes: Elasmobranchii) from the Upper Triassic of India MS Bhat, S Ray, PM Datta Geobios 51 (4), 269-283 , 2018 2018 Citations: 27
A record of new lungfishes (Osteichthyes: Dipnoi) from the Carnian (Upper Triassic) of India Bhat, M.S., and Ray, S. Historical Biology 32 (2, 2020), 428–437 , 2018 2018 Citations: 17
First report of dinosaurian claws from the Late Triassic of India Rakshit, N., Bhat, M. S., Ray, S., Datta, P. M. Palaeoworld 27 (2), 179–187 , 2018 2018 Citations: 17
First record of varied archosauriforms from the Upper Triassic of India based on isolated teeth, and their biostratigraphic implications S Ray, MS Bhat, PM Datta Historical Biology 33 (2), 237-253 , 2021 2021 Citations: 15
Techniques for systematic collection and processing of vertebrate microfossils from their host mudrocks: A case study from the Upper Triassic Tiki Formation of India Bhat, M. S. Journal of the Geological Society of India 89 (4), 369-374 , 2017 2017 Citations: 12
Bone histology of dinocephalians (Therapsida, Dinocephalia): palaeobiological and palaeoecological inferences MS Bhat, CD Shelton, A Chinsamy Papers in Palaeontology 8 (1), e1411 , 2022 2022 Citations: 11
New cynodonts (Therapsida, Eucynodontia) from the Late Triassic of India and their significances MS Bhat, S Ray, PM Datta Journal of Paleontology, 1-18 , 2020 2020 Citations: 11
Bone histology of Neogene angulate tortoises (Testudines: Testudinidae) from South Africa: palaeobiological and skeletochronological implications MS Bhat, A Chinsamy, J Parkington Royal Society Open Science 10 (3) , 2023 2023 Citations: 8
A new assemblage of vertebrate microfossils from India: a window on Late Triassic biodiversity and palaeobiogeography MS Bhat IIT Kharagpur , 2018 2018 Citations: 8
Histological investigation of burnt bones: a case study of angulate tortoises from the archaeological site, Diepkloof Rock Shelter, Western Cape, South Africa MS Bhat, A Chinsamy, J Parkington International Journal of Osteoarchaeology, https://doi.org/10.1002/oa.2986 , 2021 2021 Citations: 7
Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa MS Bhat, CD Shelton, A Chinsamy Acta Palaeontologica Polonica 66 (4), 705-721 , 2021 2021 Citations: 5
Growth and life history of freshwater chelydrid turtles (Testudines: Cryptodira): A bone histological approach MS Bhat, TM Cullen Journal of anatomy , 2024 2024 Citations: 4
A new clevosaurid (Lepidosauria: Rhynchocephalia) from the Upper Triassic of India MS Bhat, D Datta, S Ray, PM Datta Journal of Vertebrate Paleontology 43 (1), e2232833 , 2023 2023 Citations: 4
Inter-element variation in the bone histology of Anteosaurus (Dinocephalia, Anteosauridae) from the Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa MS Bhat, CD Shelton, A Chinsamy PeerJ 9, e12082 , 2021 2021 Citations: 2
Multivariate analyses reveal a new assemblage of diverse and small archosauriforms (Reptilia, Diapsida) from the Upper Triassic of India Bhat, Mohd Shafi, Ray, Sanghamitra, Datta, Pradipendra Mohan 2017 Citations: 2
A new and diverse Late Triassic fish assemblage from India Bhat, M. S. International Conference on Current Perspectives and Emerging Issues in … , 2015 2015 Citations: 2
