Pseudophichthys texanus, Lin & Nolf & Steurbaut, 2022

Lin, Chien-Hsiang & Nolf, Dirk, 2022, Middle and late Eocene fish otoliths from the eastern and southern USA, European Journal of Taxonomy 814, pp. 1-122 : 32-33

Pseudophichthys texanus sp. nov.

urn:lsid:zoobank.org:act:46DD4BB0-C7AB-4250-96E6-89E32E555091

Fig. 9E–F

Pseudophichthys aff. elongatus (Sulc, 1932) – Müller 1999: 80, fig. 21/1–2.

Diagnosis

OL/OH = 1.38–1.42. Otoliths oval, moderately thick, higher in the middle. Sulcus wide, not divided into ostium and cauda, with an oblong colliculum in the center.

Etymology

The species name is derived from ‘Texas’, the state of the type locality.

Material examined

Holotype UNITED STATES OF AMERICA • Right otolith; Texas, Wall Farm 1; Weches Formation ; Fig. 9F ; IRSNB P 9974 .

Paratypes UNITED STATES OF AMERICA • 53 otoliths of which one is figured; same collection data as for holotype; Fig. 9E ; IRSNB P 9973 .

Type locality and horizon

United States of America, Wall Farm 1 (Texas), Weches Formation.

Dimensions of the holotype

Length = 2.00 mm; height = 1.91 mm; thickness = 1.43 mm.

Description

This species is characterized by oval otoliths, with a rather considerable height. The margins are smooth. The postero-dorsal rim presents a blunt angle. The dorsal rim is flat and straight; the ventral rim is curved, with a somewhat angular central portion. The rostrum is protruding, which feature is most pronounced in the holotype. The inner face is nearly flat; the outer face is convex, and the thickness of the otolith is mainly located in the posterior part. The sulcus is wide, large, and somewhat downwards inclined in its posterior end; there is no division into ostial and caudal part. A large, oblong colliculum is located in the center of the sulcus. The cristae are well delineated in the central part of the sulcus but less developed at both ends. The dorsal area is of similar size as the ventral one.

Remarks

The otoliths of this new species are characterized firstly by their oval, rounded shape, with a height/ length ratio exceeding that of most otoliths of other species of Pseudophichthys . Specimens from the Piney Point Formation of Virginia were attributed to Pseudophichthys elongatus (Sulc, 1932) by Müller (1999), but this congeneric species from the Eocene of the Aquitaine Basin, SW France, has a more elongate shape.

Stratigraphic and geographic distribution

Lutetian: Weches Formation, Texas; Dobys Bluff Tongue of Kosciusko Formation, Mississippi; Piney Point Formation, Virginia. Bartonian: Cook Mountain Formation, Mississippi; “upper” Lisbon Formation, Alabama.

Figures

Fig. 9. Fish otoliths from the US middle and upper Eocene. A–C. “Muraenesox” barrytownensis sp. nov. A–B. “Stone City beds”, Stone City Bluff, Brazos River, Texas, paratypes (IRSNB P 9969–9970). C. “Upper” Lisbon F., Barrytown, County Road 21, Alabama, holotype (IRSNB P 9971). D. Conger vetustus Frizzell & Lamber, 1962, “upper” Lisbon F., Coffeeville Landing, Alabama (IRSNB P 9972). E–F. Pseudophichthys texanus sp. nov., Weches F., Wall Farm 1, Texas. E. Paratype (IRSNB P 9973). F. Holotype (IRSNB P 9974). G–K. Pseudophichthys glaber (Koken, 1888). G–H. Wheelock M., Little Brazos River, Stenzel loc., Texas (IRSNB P 9975–9976). I–K. “Stone City beds”, Stone City Bluff, Brazos River, sample 2 from bed P, Texas (IRSNB P 9977–9979). 1 = ventral view; 2 = inner view. Scale bars = 1 mm.