Pelvic bone morphometric analysis in the dugong (Dugong dugon)

Nganvongpanit, Korakot; Cherdsukjai, Phaothep; Boonsri, Burin; Buddhachat, Kittisak; Kaewmong, Patcharaporn; Kittiwattanawong, Kongkiat

doi:10.1038/s41598-020-76545-w

Cited by 3 publications

(2 citation statements)

References 27 publications

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“…BTD analyses instead placed E. aegyptiacum as one of the most basal stem sirenians, only one split more advanced than Protosirenidae. Even the later occurring Eotheroides species, herein placed more crownward than E. aegyptiacum , retained femora and relatively well-developed innominate bones ( Zalmout & Gingerich, 2012 ) that would—if placed within the crown group—imply that hindlimb loss occurred independently in dugongs and manatees, which only retain pelvic vestiges ( Domning, 1991 ; Fagone, Rommel & Bolen, 2000 ; Nganvongpanit et al, 2020 ). The exclusion of Eotheroides from crown Sirenia allows for a last common ancestor of extant sea cows that would have lacked hindlimbs entirely.…”

Section: Discussionmentioning

confidence: 95%

Total evidence time-scaled phylogenetic and biogeographic models for the evolution of sea cows (Sirenia, Afrotheria)

Heritage

Seiffert

2022

PeerJ

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Molecular phylogenetic studies that have included sirenians from the genera Trichechus, Dugong, and Hydrodamalis have resolved their interrelationships but have yielded divergence age estimates that are problematically discordant. The ages of these lineage splits have profound implications for how to interpret the sirenian fossil record—including clade membership, biogeographic patterns, and correlations with Earth history events. In an effort to address these issues, here we present a total evidence phylogenetic analysis of Sirenia that includes living and fossil species and applies Bayesian tip-dating methods to estimate their interrelationships and divergence times. In addition to extant sirenians, our dataset includes 56 fossil species from 106 dated localities and numerous afrotherian outgroup taxa. Genetic, morphological, temporal, and biogeographic data are assessed simultaneously to bring all available evidence to bear on sirenian phylogeny. The resulting time-tree is then used for Bayesian geocoordinates reconstruction analysis, which models ancestral geographic areas at splits throughout the phylogeny, thereby allowing us to infer the direction and timing of dispersals. Our results suggest that Pan-Sirenia arose in North Africa during the latest Paleocene and that the Eocene evolution of stem sirenians was primarily situated in the Tethyan realm. In the late Eocene, some lineages moved into more northern European latitudes, an area that became the source region for a key trans-Atlantic dispersal towards the Caribbean and northern-adjacent west Atlantic. This event led to the phylogenetic and biogeographic founding of crown Sirenia with the Dugongidae-Trichechidae split occurring at the Eocene-Oligocene boundary (~33.9 Ma), temporally coincident with the onset of dropping global sea levels and temperatures. This region became the nexus of sirenian diversification and supported taxonomically-rich dugongid communities until the earliest Pliocene. The Dugonginae-Hydrodamalinae split occurred near Florida during the early Miocene (~21.2 Ma) and was followed by a west-bound dispersal that gave rise to the Pacific hydrodamalines. The late middle Miocene (~12.2 Ma) split of Dugong from all other dugongines also occurred near Florida and our analyses suggest that the Indo-Pacific distribution of modern dugongs is the result of a trans-Pacific dispersal. From at least the early Miocene, trichechid evolution was based entirely in South America, presumably within the Pebas Wetlands System. We infer that the eventual establishment of Amazon drainage into the South Atlantic allowed the dispersal of Trichechus out of South America no earlier than the mid-Pliocene. Our analyses provide a new temporal and biogeographic framework for understanding major events in sirenian evolution and their possible relationships to oceanographic and climatic changes. These hypotheses can be further tested with the recovery and integration of new fossil evidence.

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Section: Discussionmentioning

confidence: 95%

Total evidence time-scaled phylogenetic and biogeographic models for the evolution of sea cows (Sirenia, Afrotheria)

Heritage

Seiffert

2022

PeerJ

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“…In the dugong study, we collaborated with the Phuket Marine Biological Center which provided all samples for the study. We determined that the morphometry of the dugong skull (Nganvongpanit et al 2017a), os coxae (Nganvongpanit et al 2020a), and scapula (Nganvongpanit et al 2017a) could be used as a tool for sex classification. Scapular morphology of the dugong using the caudal border tubercle and coracoid process resulted in 91.30% and 96.15% accuracy rates, respectively for identifying males and females (Nganvongpanit et al 2017a).…”

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confidence: 99%

A lesson from our institute; Why do veterinary schools need an anatomy museum?

Kongtueng¹,

Yotanyamaneewong²

2021

VIS

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Anatomy has always been a key discipline in the field of veterinary medicine, as this fundamental scientific discipline offers vital foundational knowledge on how the structure of an organ relates to its function and health. It demonstrates how the three-dimensional structure of an organism relates to the physical diagnosis of a disease, as well as to help shed light on how surgical and medical approaches can be employed to treat various diseases. This review provides supportive evidence on the importance and usefulness of the anatomy museum located within our veterinary institute. Furthermore, our outcomes will encourage all veterinary schools to consider having their own on-site anatomy museum. From our experience, the practical usefulness of an anatomy museum can be divided into 4 categories that include the study of anatomy, the study of histology, elemental study, and social education. The samples housed in an anatomy museum can increase the publishing potential of all staff members of the parent institute, as well as to elevate the reputation and general recognition of the institute. Moreover, an anatomy museum can facilitate out-of-class learning opportunities for non-university educational facilities such as kindergartens, and primary or secondary schools.

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Cetacean Evolution: Copulatory and Birthing Consequences of Pelvic and Hindlimb Reduction

Cooper,

Suydam,

Thewissen

2023

Sex in Cetaceans

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The earliest fossil cetaceans (archaeocetes) dramatically shifted the shape and articulation of the pelvis and hindlimbs during the land-to-sea transition. Archaeocetes were mostly semi-aquatic “walking whales” that used powerful hindlimbs to walk on land and swim to reach new aquatic sources of food. However, skeletons of the latest diverging lineages of archaeocetes, the basilosaurids, showed that the pelvis initially lost articulation with the sacrum, and hindlimbs were reduced and encased within the body wall. Consequently, basilosaurids were no longer able to bear their weight on land and probably had a different mating strategy compared to the other archaeocetes. Basilosaurid mating behaviors were probably consistent with those of modern cetaceans, including lateral- and ventral-facing copulation. Moreover, a pelvic girdle that was no longer constrained by vertebral and limb attachments likely freed fetal development from size constraints at birth, allowing for the birth of large fetuses. This study reports new data showing growth of the pelvis with age in modern bowhead whales (Balaena mysticetus) and their implications for left-right asymmetry and sex difference in pelvic dimensions among modern cetaceans. Reproductive structures present in modern cetaceans and artiodactyls were probably present in archaeocetes, including pelvic attachment of muscles associated with erection and mobility of the penis, the ischiocavernosus, in males and the clitoris of females. Within females, transverse folds along the vaginal canal are present in some terrestrial artiodactyls, modern cetaceans, and probably archaeocetes. Vaginal folds were probably exapted to assist in successful aquatic copulation in all fossil and modern cetaceans as they may protect some sperm from the lethal effects of sea water. Taken together, shifts in the pelvic girdle of cetaceans occurred over 40 million years ago and probably required changes in mating behaviors that were consistent with those seen in modern cetaceans.

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Pelvic bone morphometric analysis in the dugong (Dugong dugon)

Cited by 3 publications

References 27 publications

Total evidence time-scaled phylogenetic and biogeographic models for the evolution of sea cows (Sirenia, Afrotheria)

Total evidence time-scaled phylogenetic and biogeographic models for the evolution of sea cows (Sirenia, Afrotheria)

A lesson from our institute; Why do veterinary schools need an anatomy museum?

Cetacean Evolution: Copulatory and Birthing Consequences of Pelvic and Hindlimb Reduction

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