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Abstract Although Calligenethlon watsoni, an enigmatic embolomere from Joggins, Nova Scotia, has been known since 1934, an in-depth description of its anatomy (including CT data) and updated taxonomic diagnosis has yet to be completed. Additionally, subsequently discovered embolomere specimens have been referred to the taxon simply if they display embolomere traits. As a result, Calligenethlon is represented by a collection of specimens united on the basis of largely non-diagnostic traits. Here, the exquisitely preserved specimen identified as Calligenethlon, NSM 994GF1.1, is described in detail using micro-computed tomography. Comparison of this specimen to the holotype supports its referral to Calligenethlon and the anatomical knowledge gained here allows for the generation of a more robust morphological diagnosis of the genus Calligenethlon. We then re-evaluate all other referred specimens to determine which are consistent with their referral to the taxon, and which are inconclusively referred to the taxon. These data are discussed as they provide new insights into the anatomy of Calligenethlon and the diversity of embolomeres at the Joggins’ locality.
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Unveiling the elusive: X‐rays bring scolecophidian snakes out of the dark
Abstract Scolecophidian snakes have long posed challenges for scholars interested in elucidating their anatomy. The importance, and relative paucity, of high‐quality anatomical data pertaining to scolecophidians was brought into sharp focus in the late 20 th century as part of a controversy over the phylogeny and ecological origin of snakes. The basal position of scolecophidians in the phylogeny of snakes makes their anatomy, behavior, ecology, and evolution especially important for such considerations. The depauperate fossil record for the group meant that advances in understanding their evolutionary history were necessarily tied to biogeographic distributions and anatomical interpretations of extant taxa. Osteological data, especially data pertaining to the skull and mandible, assumed a dominant role in shaping historical and modern perspectives of the evolution of scolecophidians. Traditional approaches to the exploration of the anatomy of these snakes relied heavily upon serial‐sectioned specimens and cleared‐and‐stained specimens. The application of X‐ray computed tomography (CT) to the study of scolecophidians revolutionized our understanding of the osteology of the group, and now, via diffusible iodine‐based contrast‐enhanced computed tomography (diceCT), is yielding data sets on internal soft anatomical features as well. CT data sets replicate many aspects of traditional anatomical preparations, are readily shared with a global community of scholars, and now are available for unique holotype and other rare specimens. The increasing prevalence and relevance of CT data sets is a strong incentive for the establishment and maintenance of permanent repositories for digital data.
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- Award ID(s):
- 1902242
- PAR ID:
- 10448517
- Date Published:
- Journal Name:
- The Anatomical Record
- Volume:
- 304
- Issue:
- 10
- ISSN:
- 1932-8486
- Page Range / eLocation ID:
- 2110 to 2117
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/ar.24729
