Spariformes Bleeker, 1876

Lin, Chien-Hsiang, Ou, Hsin-Yueh, Lin, Chia-Yen & Chen, Hong-Ming, 2022, Garypus sanasai Lin, Huang & Chang 2022, sp. nov., Zoological Studies 61 (10), pp. 1-14 : 5-9

Order Spariformes Bleeker, 1876 Family Sparidae Rafinesque, 1818 Genus Pagrus Cuvier, 1816

Type species: Pagrus pagrus ( Linnaeus, 1758) by absolute tautonymy. Mediterranean and Atlantic.

Pagrus major ( Temminck and Schlegel, 1843) ( Fig. 2 ; Fig. S1A )

Description: The nodule itself is large and robust; it contains an almost complete lower part (splanchnocranium) of a left skull, fragmentary right premaxilla (Pmx) and dentary (Den), and the anterior part of the body. Fragments of the coracoid and cleithrum are visible just behind the opercle (Op). The body part is largely covered by fragmented scales. The description is based on the skull part.

The length of the skull is up to 94.60 mm, and the height is 73.50 mm. All associated bones are viewed from the inner (mesial, proximal) side. A fragmented right premaxilla and dentary are best visible from the dorsal view ( Fig. 2B ). The neurocranium is nearly missing, and gill skeletons are not preserved. Infraorbital bones and otoliths are absent.

The mouth is obtuse but not protruding anteriorly. The oral jaws are up to 29.40 mm in length. The ascending process of the left premaxilla (as.p.pm) is covered (obviously fused) by the right one, which is broken, and at least two pulp cavities of the caniniform teeth are exposed. Two caniniform teeth (2.04 and 6.08 mm, respectively) are attached to the nearby matrix. The tooth field of the alveolar process is elongate, accommodating two series of anterior conical (2–3 teeth, tilted) and posterior molariform (6 teeth, 1.57– 2.14 mm) teeth ( Fig. S1A ). The proximal series of the teeth is in situ, whereas in the labial (distal) one, teeth are dislodged and tilted in the surrounding matrix. The conical teeth are very slightly smaller than the molariform ones, and the latter are not progressively larger or become stout posteriorly. At least two indistinct rows of tiny villiform teeth (0.55–0.60 mm each) are present along the proximal edge of the premaxilla; they appear to be more densely spaced anteriorly and can be extended sparsely to the rear molariform teeth ( Fig. S1A ). In the maxilla (Mx), the maxillary dorsal crest (mdc) is broad and well-developed. The maxilla anteriorly articulates with the articular process of the premaxilla (ar.p.pm), and its ventral rim adjoins the dorsal roof of the premaxillary alveolar process (al. p.pm).

In the lower jaws, the left dentary, articular (Art) and angular (An), and part of the right dentary are recognized. The right dentary is better observed from the dorsal view; two caniniform teeth (2.43 and 4.72 mm, respectively) in the anterior tip and two pulp cavities of the conical teeth are preserved ( Fig. 2B ). In the left dentary, the coronoid process (cp) is well-developed and broadly extending upwards. Caniniform teeth are not seen from the surface. Two series of conical (6 teeth, 1.72–1.80 mm) and molariform (7 teeth, 1.67–2.30 mm) teeth are exquisitely preserved in the tooth field ( Table S1). The pattern of these teeth on the dentary is very similar to that of the upper jaw.

Similarly, as in the premaxilla, numerous villiform teeth are present on the proximal rim of the dentary, though many of them are shed, leaving only the pulp cavities. The articular articulates with the dentary and quadrate (Q), and its descending process (d.p.art) seems to be extending below the dentary ventral margin (character no. 39 in Day 2002), but it is not clear if it extends further beyond the symphyseal process because the latter is not observable. The jaw joint between the articular and quadrate is in the level of anterior margin of the orbit. The angular is rudimentary but still evident in the quadrate-articular facet.

In the suspensorium bones, the palatine arch, the endopterygoid (Enp), metapterygoid (Mpt), and quadrate, and possibly the palatine (Pl), are evident, but these are only fragmentary and less preserved. The hyomandibular is not preserved. Bones of the opercular region are visible but not well-preserved and indistinct; of these, the preopercle (Pop) is best distinguished and apparently has a very long ascending process with a smooth posterior margin. Other hyoid-associated skeletons are less preserved and not recognized here. A single branchiostegal ray (Brr) is preserved.

Figures

Fig. 2. Pagrus major (Temminck and Schlegel, 1843), ASIZF0100141, from the Late Pleistocene Szekou Formation, Hengchun Peninsula, southern Taiwan. A, Lateral view of the nodule. B, Dorsal view of the anterior part of the nodule, note that fragments of the right jaws are exposed. C, Drawing of the recognized skull parts. See text for anatomical abbreviations. Scale bars = 10 mm.

Fig. 1. Sampling site (A, B) and stratigraphic correlation (C) on the Hengchun Peninsula. (B) Szekou locality (black circle; modified from Chen 2016).