Protohimantura, Marramà & Klug & Vos & Kriwet, 2018

Marramà, Giuseppe, Klug, Stefanie, Vos, John De & Kriwet, Jürgen, 2018, Anatomy, relationships and palaeobiogeographic implications of the first Neogene holomorphic stingray (Myliobatiformes: Dasyatidae) from the early Miocene of Sulawesi, Indonesia, SE Asia, Zoological Journal of the Linnean Society 184, pp. 1142-1168 : 1145

GENUS † PROTOHIMANTURA GEN. NOV.

u r n: l s i d: z o o b a n k. o r g: a c t: C 1 D 0 B 6 9 3 - 3 0 0 C - 42C5-9019-30211ACED3BF

Type species: † Trygon vorstmani de Beaufort, 1926 .

Etymology: From the Ancient Greek word prōto, meaning ‘first’, ‘foremost’, ‘earliest form of’, and Himantura , one of the living whipray genera, thus indicating a possible close relationship between both taxa.

Diagnosis: A whipray characterized by the following combination of characters and body proportions: eye small; interorbital width/eye diameter ratio of 3.5; nasal capsule width/neurocranial length ratio of 0.7; nasal capsule length/neurocranial length ratio of 0.2; anteroposterior fontanelle/neurocranial length ratio of 0.8; scapulocoracoid width/lateral face length ratio of 2.2; 55 propterygial radials; 17 mesopterygial radials; mid-dorsal surface of disc covered by heart-shaped denticles arranged in an antero-posteriorly directed patch having sharply defined outlines; teeth with semiovoid or subhexagonal crown with a second transverse keel; lingual and labial crown ornamentation absent.

Remarks: The species † Trygon vorstmani was created by de Beaufort (1926) who presented a short description (one page long) and figured this single specimen in part and counterpart, which was previously collected by Professor Brouwer at the beginning of the 20th century near Patoenoeang Asoe E in the Maros district of SW Sulawesi, Indonesia. The placement of this taxon in the family Dasyatidae [= Trygonidae of de Beaufort (1926)] was based on the presence of a propterygium that is bent inwards in front to the median line and pectorals of both sides meeting at the snout( de Beaufort,1926).However,after this first brief report, no in-depth morphological analysis or identification of characters was provided to distinguish the specimen from other extant or extinct rays, with the exception of a preliminary study by Klug & Kriwet (2012) who recognized its close relationship with the genus Himantura . However, at present, Trygon is regarded as a junior synonym of Dasyatis Rafinesque, 1810 , and the Sulawesi species shows several morphological features that distinguish it from Dasyatis , Himantura and all representatives of the family Dasyatidae (see Description and Discussion). On the contrary, the morphological characters observed in the examined specimen and discussed below corroborate the erection of a new genus to contain † Trygon vorstmani and its inclusion in the subfamily Urogymninae .