Lentiarenium Manja Voss & Björn Berning & Erich Reiter 2016, gen. nov.

Genus Lentiarenium Voss gen. nov.

urn:lsid:zoobank.org:act:A67C71FB-CBC3-460E-953C-5774A3EA9939

Halitherium cristolii Fitzinger, 1842

Dugongid based on the following combination of synapomorphies: absence of alisphenoid canal, open foramen ovale, loss of permanent ffth premolar, and squamosal reaching temporal crest. Differs from the Dugonginae (Crenatosiren Domning, 1991, Nanosiren Domning & Aguilera, 2008, Dugong Lacépède, 1799, Rytiodus Lartet, 1866, Corystosiren Domning, 1990, Callistosiren Vélez-Juarbe & Domning, 2015, Bharatisiren Bajpai & Domning, 1997, Domningia Thewissen & Bajpai, 2009, Kutchisiren Bajpai, Domning, Das, Vélez-Juarbe & Mishra, 2010, Dioplotherium Cope, 1883 and Xenosiren Domning, 1989), the Hydrodamalinae Simpson, 1932 (Dusisiren Domning, 1978 and Hydrodamalis Retzius, 1794), and other dugongid genera (Eotheroides Palmer, 1899, Prototherium De Zigno, 1887, Eosiren Andrews, 1902, Caribosiren Reinhart, 1959, Priscosiren Vélez-Juarbe & Domning, 2014b, Metaxytherium De Christol, 1840, and other species formerly lumped under “ Halitherium ”) by displaying the following unique combination of plesiomorphies: frontal roof fat; supraorbital process of the frontal dorsoventrally fattened with well-developed, prominent posterolateral corner; supraoccipital wider dorsally than ventrally; exoccipitals meet in a suture dorsal to the foramen magnum; posttympanic process with a prominent anteroventral process for attachment of m. sternomastoideus; paroccipital process of exoccipital long, reaching as far ventrally as occipital condyles; accessory mental foramina present; horizontal ramus of mandible slender dorsoventrally; permanent premolars (P2/p2 – P4/p4) present. Synapomorphies: nasals reduced and not meeting in midline (shared with Eosiren imenti Domning et al., 1994, Caribosiren, Priscosiren, and all later dugongid taxa), nasal incisure at posterior end of the mesorostral fossa deep, extending posterior to the supraorbital processes of the frontals (shared with some Metaxytherium spp., dugongines, and Hydrodamalis); strongly concave ventral border of the horizontal mandibular ramus (shared with Priscosiren, Metaxytherium spp., and dugongines), masticating surface of mandible broad (shared with Metaxytherium ssp., dugongines, and hydrodamalines). In contrast to the similar species Priscosiren atlantica it has a supraorbital process with the posterolateral corner projecting posteriorly; prominent temporal crests on frontal and parietal; supraoccipital distinct in height, only slightly wider than high.

A combination of the Latin terms for the Linz Sands (Lentia and arenium), the informal name for the upper Oligocene sediments in which the species was found.