At the beginning of the 21st century, the discovery of an involucrum on the auditory bulla of Indohyus, a small raoellid artiodactyl from the Indian subcontinent, triggered the phylogenetic gathering of Raoellidae with the Cetacea clade, making them pivotal in addressing questions surrounding the land-to-water transition in Artiodactyla. Micro CT scan investigations and newly collected material from the Kalakot area (Jammu and Kashmir, India), recently greatly increased our knowledge of the cranial and dental features of this group. Here we present new data on cranial morphology of Raoellidae deriving from micro CT scan investigations of Indohyus indirae and Khirtharia inflata. This new body of data comprises investigations of the endocast of the braincase, the complete middle ear including the ossicles and auditory bulla, the petrosal bone, and the cast of the bony labyrinth. It also includes the reconstruction of the complete anterior dentition. This study gives us a comprehensive picture of the features of the Raoellidae head and improves our understanding of their semiaquatic habits. This increased knowledge of raoellids further extends the list of features they share with the first archeocetes, calling into question the definition of the clade Cetacea.
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RBINS Staff Publications 2025 OA
The New Caledonian Archipelago is a hot spot for biodiversity and endemism. Here, we report on new records of nine species from localities on the main island, Grande Terre, and illustrate these: Ilyodromus viridulus (Brady, 1886), Stenocypris hislopi Ferguson, 1969, S. macedonica Petkovski & Meisch, 1996¸ S. malayica Victor & Fernando, 1981, Bradleytriebella lineata (Victor & Fernando, 1981), Hemicypris pyxidata (Moniez, 1892), Heterocypris incongruens (Ramdohr, 1808), Cypridopis vidua (O.F. Müller, 1776) and Limnocythere stationis Vávra, 1891. We also provide redescriptions and illustrations of the valves and carapace of Stenocypris marginata Daday, 1910 sensu Méhes, 1939, Cypris granulata Daday, 1898 and Kennethia major (Méhes, 1939); for the latter species also including some soft parts. Therefore, twenty two certain species have thus far been reported from the New Caledonian Archipelago. The status of seven uncertain species is also discussed. Previous records of Stenocypris major (Baird, 1859) from Grande Terre, mainly by Méhes, are here considered to belong to S. hislopi. We propose to reject the presence of Cyprinotus cingalensis Brady, 1886 in New Caledonia and suggest to consider Cypridopsis sarasini Méhes, 1939 as an “uncertain species” (sensu Meisch et al. 2019). We also argue that Eucypris wolffhuegeli Méhes, 1914 might be a synonym of H. incongruens and suggest that Strandesia rouxi Méhes, 1939 might be considered a junior synonym of an existing species, pending further research.
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RBINS Staff Publications 2024
