Published December 31, 2021 | Version v1
Taxonomic treatment Open

Pseudorhinobatos Marramà & Carnevale & Naylor & Varese & Giusberti & Kriwet 2021

Description

GENUS † PSEUDORHINOBATOS

Zoobank registration: urn:lsid:zoobank.org:act: 75367FF8-9DCA-406F-B257-8A34595CE1BF

Type species: Trygonorhina dezignii Heckel, 1853.

Etymology: After the Ancient Greek ψεῦδος (pseudos), false, and Rhinobatos, one of the living rhinobatid genera, therefore remarking their apparent similarity; gender masculine.

Diagnosis: A rhinobatid guitarfish characterized by a wedge-shaped pectoral disc, longer (44.8% TL) than wide (38.5% TL); head length (from snout to scapulocoracoid) 29.8% TL; tail length (from pelvicfin origin to the posteriormost tip) 56% TL; pelvic-fin length 17.8% TL; snout to pelvic-fin origin 44.8% TL: well-developed lateral skin folds extending along the lateral margins of tail; rostral cartilage about 65% of neurocranial length; no horn-like processes on nasal capsules; 42 nasal lamellae; nuchal cartilages absent; anteriormost synarcual centrum located near the midlength of the synarcual; 118–138 vertebral centra, of which 18 monospondylous, and 100–120 diplospondylous; about 20 rib pairs; propterygia extending close to the margins of the pectoral disc; first propterygial segment not reaching the level of nasal capsules; propterygial radials extending as far as nasal capsule level; 60–62 pectoral-fin radials, of which 30–32 propterygial, seven to nine mesopterygial, one to two neopterygial, 20–22 metapterygial; about 21 pelvic-fin radials; closely arranged, small dermal denticles forming a continuous and regular covering on the ventral side of the body; denticle crown smooth, rhomboidal or lozenge in shape; thorns completely covering the dorsal side of the body; thorns of globular or arrow shape with prominent ridges; teeth extremely small (up to 750 µm); crown low, not globular; lingual visor slightly convex; regular central lingual uvula with apices rounded and not enlarged; two very incipient, not divergent, lateral lingual uvulae; labial apron absent; transverse keel separating the crown into labial and lingual faces, and forming a wide obtuse angle in lingual view; enameloid surface completely smooth; holaulacorhizid root bilobed, wide, displaced lingually, not broader or higher than the crown; root lobes triangular in shape in basal view, with regular, not undulated margins; lobes separated by a marked and deep furrow exhibiting a single central nutritive foramen; two additional foramina on lingual root face; low collar on upper part of the root stem.

Notes

Published as part of Marramà, Giuseppe, Carnevale, Giorgio, Naylor, Gavin J. P., Varese, Massimo, Giusberti, Luca & Kriwet, Jürgen, 2021, Anatomy, taxonomy and phylogeny of the Eocene guitarfishes from the Bolca Lagerstätten, Italy, provide new insights into the relationships of the Rhinopristiformes (Elasmobranchii: Batomorphii) in Zoological Journal of the Linnean Society 192

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Linked records

Additional details

References

  • Heckel MJ. 1853. Bericht uber die vom Herrn Cavaliere Achille de Zigno hier angelangte. Sammlung fossiler Fische. Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Klasse 11: 122 - 138.