O. 1997. A rare find of a vomerine tooth plate of an elephant fish (Holocephali,
Callorhynchidae) in the Upper Cretaceous of Russia. Paleontologicheskii
Zhurnal, No. 1: 78-80.
Translated by Oleg Lebedev
A vomerine tooth plate of an elephant fish Callorhinchus
sp. from the Upper Santonian of the Penza Region [of Russia] is
Extant elephant fishes (Callorhinchus ) inhabit temperate
and subpolar basins of the Southern Hemisphere. Extremely rare finds of
Callorhinchus are known from the Upper Jurassic of England
and Russia (WOODWARD, 1892; WARD & McNAMARA, 1977; AVERIANOV, 1992),
Cretaceous of Russia (NESSOV et al., 1986) and New Zealand (NEWTON, 1876),
Paleocene and Eocene of England (GURR, 1963; WARD, 1973) and Cenozoic
of Argentina(WOODWARD & WHITE, 1930). Egg capsule imprints that probably
belonged to the callorhynchids are described from the Upper Jurassic of
Yakutia (OBRUCHEV, 1966). In Callorhynchidae, as in all other members
of the Chimaeroidei, the dentition consists of two pairs of tooth plates
(vomerine and palatine) in the upper jaw and a pair (mandibular) in the
lower one (PATTERSON, 1965). Up to the latest times, only palatine and
mandibular callorhynchid tooth plates were found as fossils. Two vomerine
tooth plates ascribed to a new species were discovered recently by L.
A. NESSOV in the Albian (Lower Cretaceous) of the Belgorod Region, Russia.
A new find of a Callorhinchus tooth plate comes from the
Upper Santonian (Upper Cretaceous) deposits of the Penza Region close
to the village of Kikino; it was collected in 1995 by the author and A.
V. PANTELYEV. This specimen is stored in the Zoological Institute of the
Russian Academy of Sciences (ZIN PC). The author thanks A. V. PANTELYEV
for sorting, etc....
The vomerine tooth plate, Callorhinchus sp., is comparatively
very narrow; the maximum width/length ratio is 0.33 (Fig. 1). The symphyseal
margin is almost straight, and the labial one bears a deep S-shaped notch.
The anterior end of the plate forms a hook-shaped (in the parasagittal
plane) "beak" that descends significantly lower than the ventral plane
of the plate. A row of six longitudinally elongated narrow tritors of
various lengths is situated on the ventral surface by the symphyseal margin.
A long and thin lingual process directed posteriorly is situated in the
posterior part.The symphyseal surface does not extend to the lingual process.
A clearly marked descending lamina, parallel to the labial edge, is situated
on the dorsal surface of the tooth plate. Medially, the latter bears characteristic
ornamentation composed of longitudinally elongated crests and furrows.
The distance between the "beak" tip and the posterior part of the lingual
process is 19.1 mm.
In the fossil members of the genus Callorhinchus the vomerine
tooth plates are known only in a new species from the Albian of the Belgorod
Region. These tooth plates have no pronounced "beak", but possess a long
lingual edge and longitudinal rows of tritors on the wear surface. In
modern forms, the vomerine tooth plates are usually wide and bear a small
"beak" or are devoid of it; often they have no long lingual process (BIGELOW
& SCHROEDER, 1953, fig. 127B; GARMAN, 1904, Pl. 6, fig.1,8,9, Pl.
7, fig.7; DEAN, 1906, fig.95, 106; PATTERSON, 1992, fig.2,9A). The tooth
plate described here is most similar to the vomerine tooth plates of C.
capensis Dumeril, 1865 from the coastal basins of South Africa
(GARMAN 1904, Pl. 6, fig.5; CASE & BRAUN, 1972, fig.2C) by its S-shaped
labial edge, comparative narrowness and long lingual process. It is similar
as well to theCallorhinchus sp. tooth plates illustrated
by PICTET (1853-1857, p. 37, fig. 8,9) and C. antarcticus
McCoy, 1886 (usually regarded as a synonym of C. milii Bory
1823; however, in this species vomerine tooth plates differ in construction)
figured by JAEKEL (1901, Pl. 24, fig. 3a). At the same time, in C.
capensis and C. antarcticus the "beak" is shorter,
and in Callorhinchus sp. is longer than in C
. sp. from Kikino Village.
Previously, Late Cretaceous callorhynchid remains were known only from
the Cenomanian of the Saratov Region (E. V. POPOV, pers. comm.) and the
Cenomanian of New Zealand (NEWTON, 1876).
Apart from Callorhinchus sp., a mandibular tooth plate of
the chimaeroid Elasmodus sp., shark teeth of Acrodus
sp., Ptychodus mammilaris Ag. 1843, Synechodus
sp. cf. S. lerichei Herman 1977, S. sp. cf.
S. hesbayensis Casier 1943, Hexanchus sp., Heterodontus
sp., ?Cretorectolobus sp., Squatina sp., Eostriatolamia
sp., Cretolamna appendiculata (Ag. 1843), Cretoxyrhina
mantelli (Ag. 1843), Paracorax sp., andSqualicorax
sp., cf. S. santonicus (Glickman & Zhelezko 1979), and
teleost fish remains, including Enchodontidae teeth are known from the
Kikino Village locality.
AVERIANOV, A. O. 1992. New Jurassic chimaeras from Russia. Palaeont. J.
BIGELOW, H. B. and W. C. SCHRODER. 1953. Fishes of the Western North Atlantic,
Pt.2. Sears Found. Mar. Res., 561 p.
CASE, G. R. and M. K. BRAUN. 1972. Capture of a chimaera in False Bay,
South Africa. Underwater Nat., 7(3):28-30,48.
DEAN, B. 1906. Chimaeroid fishes and their development. Publ. Carnegie
Inst. Wash., No.32, p. 1-195.
GARMAN, S. 1904. The chimaeroids (Chismopnea Raf. 1815, Holocephala Mull.
1834), especially Rhinochimaera and its allies. Bull. Mus. Comp. Zool.,
GURR, P. R. 1963. A new fish fauna from the Woolwich Bottom Bed (Sparnacian)
of Herne Bay, Kent. Proc. Geol. Assoc., 73(4):419-447.
JAEKEL, O. 1901. Über jurassischeZähne und Eier von Chimaeriden.
Neues Jahrb. mineral., geol., paläontol. B. 14, S. 540-564.
NEWTON, E. T. 1876. On two chimaeroid jaws from the Lower Greensand of
New Zealand. Quart. J. Geol. Soc. 32:326-331.
OBRUCHEV, D. V. 1966. Fossil chimaera egg capsules. Paleont. J. No. 3:117-124.
PATTERSON, C. 1965. The phylogeny of the chimaeroids. Phil. Trans. Roy.
Soc. London, Ser. B. 249:101-219.
PATTERSON, C. 1992. Interpretation of the tooth plates of chimaeroid fishes.
Zool. J. Linn. Soc., 106(1):33-61.
PICTET, F. J. 1853-1857. Traité de Paleontologie ou histoire naturelle
des animaux fossiles considerés dans leurs rapports zoologiques
et geologiques. Paris. Atlas, 110 pl.
WARD, D. J. 1973. The English Paleogene chimaeroid fishes. Proc. Geol.
WARD, D. J. and K. J. McNAMARA. 1977. Associated dentition of the chimaeroid
fish Brachymylus altidens from the Oxford Clay. Palaeontol.,
WOODWARD, A. S. 1892. On some teeth of new chimaeroid fishes from the
Oxford and Kimmeridge Clays of England. Ann. Mag. Nat. Hist., Ser. 6,
WOODWARD, A. S. and E. I. WHITE. 1930. On some new chimaeroid fishes from
Tertiary formations. Ann. Mag. Nat. Hist., Ser. 10, 6:577-582.
Fig. 1. Left vomerine tooth plate of Callorhinchus sp., ZIN
PC, N 7/11; a, anterior; b, ventral; c, lateral; d, dorsal; e, medial.
Penza Region, Kamenka District, the left bank of the Kevda River in the
vicinity of Kikino Village; Cretaceous (Upper Santonian).
Key:B_, descending lamina; K, "beak", _O, lingual process; T, tritors.
(The "_" takes the place of letters not available on the Western keyboard.)