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  1. Abstract

    We report a new genus and species of herbivorous mammal,Pahelia mysteriosa, from the early Eocene Cambay Shale Formation, Tadkeshwar Lignite Mine, Gujarat, India. The new taxon, approximately the size of a small phenacodontid (e.g.Ectocion parvus), is represented by three mandibular fragments, the most complete of which documents nearly the entire symphysis and mandibular body plus P3–M3.Paheliahas incipiently selenolophodont molars with strong exodaenodonty, absent paraconids, weak but distinct entolophids, and prominent ectostylids. Molar size increases distally, but M3does not develop a prominent third lobe. Premolars are simple, with prominent protoconids and short talonids but little development of other trigonid cusps. The mandibular symphysis is strongly fused, and there is an enlarged alveolus for an anterior tooth. The combination of features present in the new taxon does not closely match that of any known mammal, but there are some similarities to a diversity of ungulates from Africa, Asia, Europe and North America. Preserved morphology is insufficient to assess the affinities of the new taxon with confidence, but a link to Quettacyonidae, also endemic to the Indian subcontinent, is morphologically and biogeographically plausible. If this scenario is correct, it suggests thatP. mysteriosacould be a part of the endemic mammalian fauna of India prior to its initial faunal contact with Asia.

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  2. Abstract

    We describe, in unprecedented detail, the petrosals and stapes of the docodontBorealestesfrom the Middle Jurassic of Scotland, using high resolution μCTand phase‐contrast synchrotron imaging. We describe the inner ear endocast and the vascularized interior structure of the petrosal, and provide the first endocranial view of a docodontan petrosal. Our study confirms some similarities in petrosal and stapedial morphology with the better knownHaldanodonof the Late Jurassic of Portugal, including: (1) the degree of curvature of the cochlea; (2) multiple features related to the highly pneumatized paroccipital region; (3) the shape of lateral trough, the fossa of the M. tensor tympani, and the ridge on the promontorium; (4) the round shape of the fenestra vestibuli; and (5) overall morphology of the stapes. ButBorealestesdiffers fromHaldanodonin having a bony ridge that separates the tympanic opening of the prootic canal, the secondary facial foramen and the hiatus Fallopii, from the fenestra vestibuli. We identify two new vascular structures: the anterior and posterior trans‐cochlear sinuses, which traverse the pars cochlearis around the cochlear nerve (VIII). These trans‐cochlear sinuses have not been observed in previous docodont specimens, and could be an autapomorphy ofBorealestes, or apomorphic for this clade. We also establish the anatomical relationship of the circum‐promontorium plexus to the inner endocast. The high quality of our scans has made these structures visible for the first time.

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