User:Amirani1746/sandbox3

Amirani1746/sandbox3 Temporal range: Late Famennian
Block containing holotype specimen of H. uldezinye
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Sarcopterygii
Clade:	Tetrapodomorpha
Clade:	Eotetrapodiformes
Family:	†Tristichopteridae
Genus:	†Hyneria Thomson, 1968
Type species
†H. lindae Thomson, 1968
Other species
†H. udlezinye Gess & Ahlberg, 2023

Hyneria is a extinct genus of large predatory lobe-finned fish that lived during the Late Devonian (Famennian). It belongs to the family Tristichopteridae, an extinct lineage of carnivorous fishes, closely related to the ancestors of tetrapods. Two species are known, H. lindae and H. udlezinye, known respectively from the fossil record of present-day North America and South Africa.

With a size generally fixed between 2.5–3 m (8 ft 2 in – 9 ft 10 in) long, all accompanied by a very specialized dentition, Hyneria was undoubtedly a large predator which would not have hesitated to attack prey with large measurements.

Research history

H. lindae

The first known fossils of Hyneria lindae were discovered in 1952 by S. R. Ebright in a large road cut on the north side of Pennsylvania Route 120, between the villages of North Bend and Hyner in Clinton County, located in Pennsylvania, USA. The precise place of this find is the site of Red Hill, a locality dating from the upper stage of the Famennian (Upper Devonian). The holotype (MCZ 9284) consists of a disarticulated skull in three blocks. This specimen is soon mentioned in a 1967 article by Keith Stewart Thomson, before being formally described and named the following year by the same author. The genus name Hyneria refers to the village of Hyner in Pennsylvania, close to the site of the discovery of the first fossil individual. The specific epithet lindae comes from the first name of Thomson's wife, the paleontologist who described the animal.

The holotype and paratype specimens were considered as the only viable fossils belonging to the taxon until 1993, when a new collecting effort began to uncover abundant new material within Red Hill, to the point of becoming one of the most abundant vertebrates in terms of presence within the Catskill Formation. Some other fossils of H. lindae have been temporarily described as belonging to other tristichopterid taxa. For example, in 1956, Alfred Romer and a team from Harvard University collected a remarkably complete specimen, which they identified as coming from Eusthenodon wängsjöi. This specimen, cataloged MCZ 8825, was reclassified as H. lindae in the genus rediagnosis conducted by Edward B. Daeschler and Jason P. Downs in 2018.

H. uldezinye

The specimens referred to the second species H. uldezinye were discovered near the town of Grahamstown in South Africa, and more precisely in the lagerstätte of Waterloo Farm, a geological site dating from the Upper Famennian, i.e. exactly the same age as the Catskill Formation. Several fossils were prepared and subsequently moved to the Albany Museum. The holotype specimen is preserved in two blocks, cataloged AM6540 and AM6528, which additionally contain bones of the stem-tetrapod Umzantsia and the placoderm Groenlandaspis. The presence of the genus Hyneria within this locality was mentioned as early as 2008, in particular on the basis of the comparison with other tristichopterids. The naming and anatomical descriptions are done by Robert W. Gess and Per E. Ahlberg and are officially published in an article in the scientific journal PLOS ONE in February 2023. The specific epithet uldezinye comes from isiXhosa and means "he who eats the others", referring to the inferred predatory lifestyle of the species. The IsiXhosa is the widely spoken native language of southeastern South Africa, where the original fossil locality of the finds is.

Description

Size

Hyneria is a bony fish of fairly large proportions, typically ranging in size from 2.5–3 m (98–118 in) in length for H. lindae. The size of the second known species, H. uldezinye, was once estimated to be between 2.5–4 m (98–157 in) long based on fossil analyzes before being described. However, the official description of the taxon shows that the largest known specimens belonging to the species measure at least 2.7 m (110 in).

Other fossil specimens attributed to the genus Hyneria seem to indicate that some representatives could have reached larger measurements, but the weak identifications of the fossil material make these assertions uncertain and require re-evaluations. While the largest known jaw of H. lindae (ANSP 21432), is 38 m (1,500 in) long, another specimen (ANSP 21434), containing the mandibular symphysis and jaw fragments, may have come from a mandible approaching twice that length. However, there are also rhizodontids in the Red Hill fauna, and therefore the specimen might not even belong to the genus, as the dental characteristics observed are present in the latter. Unpublished specimens suggest that Hyneria could have been larger, potentially measuring up to 3.5 m (140 in) in length, but the estimates are based on the dubious fossils previously mentioned and those of the related genus Eusthenopteron.

Skull

Restoration of the skull of H. udlezinye

The skull roof of Hyneria suggests a broad head with a rounded snout similar to that described for Cabonnichthys and Eusthenodon, but different from the narrow head and "very pointed" snout of Mandageria or the more torpedo-shaped head of Eusthenopteron. As in other tristichopterids, the postorbital bone is triangular in shape and elongated, with a posterior margin that ends in a postero-dorsal process. The maxilla is almost parallel in shape. The maxilla of H. lindae is even more extreme than that of H. udlezinye, in that the contact margin of the squamosal is concave rather than convex.

Hyneria's mandible is long yet slender, possessing three coronoids on both sides, two pairs of fangs on the third, and an articulated quadratojugal composed of two longitudinal pits. The fangs of the dentary bones are compressed on the lingual side and have sharp keels on both sides, beings besides very robust and being able to reach more than 5 cm (2.0 in). The row of teeth present in the mandible is aligned and extends to the mandibular symphysis. The general dentition of Hyneria suggests a predator specializing in hunting large preys, although no such interactions are known in the fossil record.

See also

• Eusthenopteron
• Eusthenodon

External links

• Hyneria lindae at Devonian Times