We here re-evaluate the skeletal anatomy and the systematic position of the two Eocene guitarfish species represented by almost complete and articulated material from the Konservat-Lagerstätten of Bolca in Italy. The analyses of morphometric, skeletal and dental features of ‘Rhinobatos’ dezignii and ‘R.’ primaevus allow them to be excluded from the living guitarfish genus Rhinobatos and assigned to the new genera †Pseudorhinobatos gen. nov. and †Eorhinobatos gen. nov., respectively. The placement of these new genera within the rhinopristiform family Rhinobatidae is based on the possession of a series of morphological features (e.g. pectoral fins fused to head forming a wedge-shaped pectoral disc; rostral cartilage extending to the tip of the snout; nuchal cartilages and hornlike processes of nasal capsules absent; teeth with Rhinobatos-like morphology displaying smooth enameloid, central uvula and two lateral uvulae) that unambiguously exclude their assignment to any other rhinopristiform family. A new morphology-based phylogenetic analysis that includes the two new fossil genera, described herein, provides novel insights into the relationships of the Batoidea and recovers the Rhinopristiformes as a paraphyletic group. This indicates that the monophyly of extant taxa could be the result of the extinction of crucial taxa.

Anatomy, taxonomy and phylogeny of the Eocene guitarfishes from the Bolca Lagerstätten, Italy, provide new insights into the relationships of the Rhinopristiformes (Elasmobranchii: Batomorphii)

Giuseppe Marrama
First
;
Giorgio Carnevale;
2021

Abstract

We here re-evaluate the skeletal anatomy and the systematic position of the two Eocene guitarfish species represented by almost complete and articulated material from the Konservat-Lagerstätten of Bolca in Italy. The analyses of morphometric, skeletal and dental features of ‘Rhinobatos’ dezignii and ‘R.’ primaevus allow them to be excluded from the living guitarfish genus Rhinobatos and assigned to the new genera †Pseudorhinobatos gen. nov. and †Eorhinobatos gen. nov., respectively. The placement of these new genera within the rhinopristiform family Rhinobatidae is based on the possession of a series of morphological features (e.g. pectoral fins fused to head forming a wedge-shaped pectoral disc; rostral cartilage extending to the tip of the snout; nuchal cartilages and hornlike processes of nasal capsules absent; teeth with Rhinobatos-like morphology displaying smooth enameloid, central uvula and two lateral uvulae) that unambiguously exclude their assignment to any other rhinopristiform family. A new morphology-based phylogenetic analysis that includes the two new fossil genera, described herein, provides novel insights into the relationships of the Batoidea and recovers the Rhinopristiformes as a paraphyletic group. This indicates that the monophyly of extant taxa could be the result of the extinction of crucial taxa.
192
1090
1110
Giuseppe Marrama, Giorgio Carnevale, Gavin J.P. Naylor, Massimo Varese, Luca Giusberti, Jurgen Kriwet
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/1766101
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 1
social impact