Parascombrops schwarzhansi, Van Hinsbergh & Helwerda, 2019

Van Hinsbergh, Victor W. M. & Helwerda, Renate A., 2019, Fish Otoliths from the Cabarruyan Piacenzian-Gelasian fauna found in the Philippines, Zootaxa 4563 (3), pp. 401-443 : 431-433

Parascombrops schwarzhansi n.sp.

(Figures 102–107)

Holotype: Anda2, RGM 962352

Paratypes: 5 specimens: Anda1 (3) RGM 962243 , RGM 962244 , RGM 962353 ; Anda2 (1) RGM 962354 ; Tiep2 (1) RGM 962249 .

Other material: 13 specimens in total. Anda1 (4) RGM 962245 ; Anda2 (4) RGM 962246 ; Anda3 (2) RGM 962247 ; Tiep1 (1) RGM 962248 ; Tiep2 (2), RGM 962250 .

Diagnosis: A moderately elongated oval-shaped Parascombrops otolith with distinct crenulation along the regularly curved ventral and dorsal rims.

Etymology: In honor of Dr. Werner Schwarzhans for his contributions on paleoichthology.

Description: The holotype is an moderately elongated oval-shaped specimen with a OL= 3.2 mm and OL:OH= 1.91. The ventral rim is regularly bent with its strongest bending at its anterior part. The dorsal rim also bends regularly, but weaker, until a weak postdorsal angle at its very posterior part. Dorsal and ventral rims are regularly ornamented with small furrows and lobes. The very posterior part of the holotype bends downwards to the ventral rim, a feature that is more rounded in most paratypes. There is a blunt rostrum and an indistinct excisural notch. The straight sulcus displays a large oval-shaped ostium and a narrower nearly straight cauda. It spans nearly the whole length of the otolith and ends in a brief postcaudal depression, which slightly bends in posterior-ventral direction. The outer surface is decorated with many lobes and furrows that run perpendicular to the dorsal and ventral rims to a central flat area that runs in the mid-central part along the otolith. The paratypes resemble the holotype very well; the OL:OH ratio ranges between 1.73 and ~1.90, and the posterior rim is more rounded, with a shallow postdorsal angle above the end of the cauda. In small specimens the postdorsal angle is not developed, and the postdorsal field form a bluntly pointed extension behind the cauda, which gives the otolith a rounded spindle-shape impression.

PLATE 9.

93. Sparidae indeterminate, RGM 962339, locality Anda2.

94. Owstonia nigromarginatus , RGM 962277, locality Roxas.

95. Owstonia nigromarginatus , RGM 962275, locality Anda2.

96. Owstonia nigromarginatus , RGM 962278, locality Roxas.

97. Owstonia nigromarginatus , RGM 962274, locality Anda2, SEM image.

98. Owstonia sp., RGM 962272, locality Anda6.

99. Owstonia sp., RGM 962271, locality Anda2.

103. Parascombrops schwar z hansi, RGM 962353, locality Anda1. (a) Medial face, (b) lateral face, (c) ventral profile. 104. Parascombrops schwar z hansi, RGM 962244, locality Anda1. (a) Medial face, (b) lateral face, (c) ventral profile. 105. Parascombrops schwar z hansi, RGM 962243, locality Anda1. (a) Medial face, (b) lateral face, (c) ventral profile. 106. Parascombrops schwar z hansi, RGM 962249, locality Tiep2. (a) Lateral face, (b) medial face.

Discussion: The specimens are reminiscent of P. ohei Schwarzhans & Prokofiev, 2017 and juvenile specimens of P. argyreus Schwarzhans & Prokofiev, 2017 (also depicted by Rivaton & Bourret (1999) as P. adeni ). However, they are more rounded and less elongated than P. ohei , and, display a very characteristic crenulation along their dorsal and ventral rims. One larger otolith (7.2 mm), RGM 962251, was encountered in Anda4, which may represent a strongly polished and therewith poorly preserved adult specimen of Parascombrops . Its size and estimated shape may suggest Parascombrops argyreus (Gilbert &Cramer, 1897) , but its preservation state does not allow definitive species identification.

Distribution: Plio-/Pleistocene of northwest Philippines.