Xiphiorhynchoides

Xiphiorhynchoides; Temporal range: Early Oligocene PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Carangiformes
Family:	Xiphiidae
Genus:	†Xiphiorhynchoides; Fierstine & Pfeil, 2009
Type species
	†Xiphiorhynchoides haeringensis; Fierstine & Pfeil, 2009

Xiphiorhynchoides is an extinct genus of swordfish from the Oligocene of Austria. Its fossils have been found in the Paisslberg Formation in Tyrol, which is thought to represent a deepwater environment close to the shore. It is the best preserved member of the Xiphiorhynchinae and known from a single species: X. haeringensis. The name derives from the town of Bad Häring.

Description

Xiphiorhynchoides is known from its skull and the front areas of the body. It resembles Xiphiorhynchus in several anatomical details such as the paired premaxillae that fuse towards the end of the rostrum and the presence of fine and elongated (villiform) teeth. Like its relative, both the upper jaw and lower jaw were elongated and equal in length, which differentiates them from modern swordfish.^[1] However it can be distinguished from Xiphiorhynchus by the fused mandibular symphysis of the lower jaw, a large hyoid and the complete suspensorium. Additionally, it appears to entirely lack the nasal bones and possesses an elongated ethmoid bone. The holotype preserves the dorso-ventrally aligned pectoral girdle and its fins along with the dorsal fin and anal fins.^[2]

References

^ Friedman, M.´; Otero, R.A. (2009). "First fossil billfish (Perciformes: Xiphiidae) from central Chile" (PDF). Congreso geológico Chileno XII, symposium 10, abstract. 29.
^ Fierstine, H. L.; Pfeil, F. H. (2009). †Xiphiorhynchoides haeringensis, a new genus and species of billfish (Perciformes: Xiphoidei: Xiphiidae: †Xiphiorhynchinae) from Bad Häring, Tyrol, Austria, Lower Oligocene (NP 22). Palaeo Ichthyologica. Vol. 11. Verlag Dr. Friedrich Pfeil. pp. 5–42. ISBN 978-3-89937-095-9.

[Fr09-1] Friedman, M.´; Otero, R.A. (2009). "First fossil billfish (Perciformes: Xiphiidae) from central Chile" (PDF). Congreso geológico Chileno XII, symposium 10, abstract. 29.

[F09-2] Fierstine, H. L.; Pfeil, F. H. (2009). †Xiphiorhynchoides haeringensis, a new genus and species of billfish (Perciformes: Xiphoidei: Xiphiidae: †Xiphiorhynchinae) from Bad Häring, Tyrol, Austria, Lower Oligocene (NP 22). Palaeo Ichthyologica. Vol. 11. Verlag Dr. Friedrich Pfeil. pp. 5–42. ISBN 978-3-89937-095-9.

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