Contr. Tert. Quatern. Geol. 34(3-4) 151-155 2 figs, 1 pi. Leiden, October 1997
Otoliths of a new sciaenid fish (Pisces, Teleostei) from
the Zonderschot Sands Member (Miocene) of Belgium
Kristiaan Hoedemakers
MORTSEL, BELGIUM
Hoedemakers,Kristiaan. Otoliths of a new sciaenid fish (Pisces, Teleostei) from the Zonderschot Sands Member (Miocene) of Belgium. —
Contr. Tert. Quatem. Geol., 34(3-4): 151-155, 2 figs, 1 pi. Leiden,October 1997.
Several large otoliths ofa sciaenid fish collected from two temporary outcrops ofthe Zonderschot Sands Member (Miocene) at Heist-op-den-
Sciaenidarum’ Its discussed and the of these Berg (Belgium) represent a new taxon, ‘genus heistensis n. sp. affinities are stratigraphy outcrops
is described.
— Sands Member, Miocene, Key words Pisces, Teleostei,new taxon, Zonderschot Belgium.
K. Hoedemakers, Minervastraat 23, B-2640 Mortsel, Belgium.
Contents Introduction
Introduction p. 151 As part of the Berchem Formation, the Zonderschot Sands
Localities and stratigraphy p. 152 Member was introduced by De Meuter & Laga (1976), who
This view Systematic palaeontology p. 153 considered it to be of middle Miocene age. was
followed & Nolf On the basis of Acknowledgements p. 154 by Huyghebaert (1979).
References p. 154 planktonic foraminifera, however, Hooyberghs (1980, 1996)
favoured an early Miocene (Burdigalian) age.
Fig. 1. Map showing the Lostraat (1) and Bergebeekstraat (2) temporary outcrops at Heist-op-den-Berg. 152
Fig. 2. Lithostratigraphy of strata exposed in the temporary outcrops at the Lostraat and Bergebeekstraat (Heist-op-den-Berg).
The otolith faunas of the Zonderschot Sands Member were sediments encountered at these localities are described here described Nolf and studied in detail noted excavation and by (1977) by Huyghe- (Fig. 2). Differences were during baert & Nolf (1979), who recognised 67 taxa in their sam- sampling: at the Lostraat the Zonderschot Sands Member
view of the fact that the fauna of 3 the of the unit 2 ples. In remaining was not was exposed to a depth m, top lying at considered at that time, members of the 'Belgische Vereni- m below surface. Sediments in this portion of the member ging voor Paleontologie (BVP)' undertookfour excavations are clayey and highly fossiliferous; they were exposed in
which of the between 1989 and 1995 during about 50 tonnes of three separate pits in 1989, 1991 and 1993. The top fossiliferous sediment wet-sieved. taken for reached in were Samples underlying Boom Clay Member(Oligocene) was micropalaeontological analyses have recently been described a borehole at 4.40 m below surface. The section between 3 by Hooyberghs (1996), and selected molluscan species and 4.40 m proved much less fossiliferous and much more collected from these temporary outcrops will shortly be clayey. published (Marquet, 1997). At the Bergebeekstraat, where a 5 m deep pit was dug,
2.5 m of Quaternary deposits were found to rest on the
least 2.5 thick. Zonderschot Sands Member, which was at m
LOCALITIES AND STRATIGRAPHY Here strata were found to be more fossiliferous towards the
and bottom of the pit (where a thin mollusc layer occurred) the coral less so towards the top where a thin layer of Fla- The Zonderschot Sands Memberwas exposed in the imme-
bellum was Bulk samples were taken from the diate vicinity of the type locality of that unit (co-ordinates, x sp. present. lowermost two metres only. On account of extreme ground = 176.520, y = 194.6(X)) at the Lostraat and Bergebeekstraat,
water conditions, the Boom Clay Member could not be both alongside the Bergebeek, near the hamlet of Zonder- reached in this pit. schot (municipality of Heist-op-den-Berg, province of Ant- werp) (Fig. 1). The co-ordinates (topographic map of Belgi-
these — Lostraat section (in metres below surface): um, scale 1:25 (XX), sheet 24/1-2) of localities are as follows:
0.00-0.50 Recent soil
0.50-1.05 slightly clayey brown sand Locality 1 (Lostraat): x = 175.775, y = 194.450 1.05-1.65 sand slightly clayey green/light grey Locality 2 x = 175.920, = 194.330 (Bergebeekstraat): y 1.65-2.00 heavy green clay
2.00-3.00 dark brown, clayey, glauconitic sand with shells and Since the is known from borehole the stratotype a only, frost wedges 153
3.00-4.40 dark brown sand with few very clayey, glauconitic IRSNB P 7096 22.0 6.5 7.0
shells
4.40-4.50 heavy clay grey Affinities — The Zonderschot Sands Member has yielded
otoliths of three sciaenid taxa (Huyghebaert & Nolf, 1979),
— Bergebeekstraat section (in metres below surface): and Sciaenidarum' viz.Argyrosoma sp., Umbrina sp. 'genus
teutonicus Weiler, 1942. As will be discussed furtherbelow,
0.00-0.80 Recent soil the present material does not belong to the genus.Argyrosoma 0.80-1.85 brown sand De la Pylaie, 1835, and the otolithof Umbrina s p. is much sand 1.85-2.50 green clayey more clearly bent in the anteroposterior direction and is much 2.50-2.80 light brown sand with shells, shell hash and frost higher than the new species described herein. However, its wedges
state of is such that further is diffi- 2.80-2.90 layer of corals (Flabellum sp.) and shells in light preservation comparison cult. 'Genus Sciaenidarum' does have slender brown, slightly clayey, glauconitic sand teutonicus not whereas the 2.90-4.90 dark brown clayey, glauconitic sand, rich in disper- otoliths, the ostium is much smallerand deeper
sed shells cauda has a marked crista superior and is not so clearly bent
4.90-5.00 of shells in dark brown in Schwarzhans layer clayey, glauconitic as 'genus Sciaenidarum' heistensis. (1993, sand Sciaenidarum' in the Acro- p. 12) placed 'genus teutonicus
pomatidae, but comparison with otoliths of Recent acropo-
The otoliths described in the were collected present paper matidsand sciaenids[Cynoscion striatus (Cuvier, 1829) and
from the 2.00-3.00 m interval at the Lostraat, and from the Seriphus politus Ayres, 1860] shows that it is a true sciaenid, 2.90-4.90 m interval at the Bergebeekstraat. of indeterminate generic status.
Radwanska recorded (1992, pp. 265, 266) a juvenile
sciaenid otolith in open nomenclature, 'genus Sciaenidarum' SYSTEMATIC PALAEONTOLOGY of Poland, which is sp., from the middleMiocene completely
different from the Belgian specimens, being very round, high
Sciaenidarum’heistensis n. sp. ‘genus and convex and with a short ostium and an entirely different
PI. 1 cauda.
The otoliths of 'genus Sciaenidarum' heistensis show a
Diagnosis — This species is characterised by slender, elon- superficial resemblance to otoliths of the genusCynoscion gate otoliths with a thin anterior portion and a rather massive Gill, 1861, in which extreme elongation is also observed in This last feature becomes in posterior part. more prominent Sasaki, 1989, a number of species (see Chao, 1978, p. 17; older The inner is specimens. face markedly convex in the p. 79; Schwarzhans, 1993, pp. 36-51 for illustrations of antero-posterior direction and nearly flat in the dorso-ventral comparative Recent material). In Cynoscion, however, the direction. The ostium is wide and covers nearly the entire posterior portion of the outer face never shows such a strong anterior halfof the face. The cauda is straight for about two thickening and the posterior end of the cauda always presents thirds of its length; its posterior end is markedly bent towards simila- a more or less circular widening. There is also some
the ventral rim, but without recurving anteriorly. The area rity to representatives ofAtractoscion Gill, 1862 (see Sch- between this curved and the of the portion posterior part warzhans, 1993, 56, 57 for illustrations of pp. comparative ostial crista inferior shows a rather elongate rectangular Recent material), but in otoliths of this genus the inner face shape. is always strongly convex in the dorso-ventral direction and
— is IRSNB P IRSNB Types Holotype 7094; paratypes are the posterior end ofthe cauda is recurved anteriorly. A third in P 7095 and P 7096, all the collections of the Institutroyal otolith certain those described type showing a similarity to des Sciences naturelles de Belgique (IRSNB), Brussels; other here has been documented inArgyrosomus (see Chaine,
are in the author's collection. specimens private 9; Trewavas, 1977, 485; Schwarzhans, 1993, 1938, pi. p. pp.
Derivationominis — After the town of Heist-op-den-Berg. 137-139for illustrations of Recent material), but in this genus
Locus and stratum — Lostraat temporary typicus typicum the otoliths have a much stronger recurved posterior part of outcrop (Zonderschot, Heist-op-den-Berg), Zonderschot the cauda. In addition, the area between the reflexed portion Sands Member (Berchem Formation, early or middle Mioce- inferior of the caudaand the posterior part of the ostial crista
ne). is and in the direction. high very narrow antero-posterior
Material— Thirteen complete specimens and several frag- Otoliths of the three genera mentioned above are of the
ments with the anteriortip broken off. elongated type, but their resemblance to the 'genus Sciaeni-
darum'heistensis is only a superficial one. For that reason, it
Dimensions (in mm) — is impossible to infer close affinities between these and the
fossil species, which is why the latteris left in open generic width length height nomenclature.
Occurrence — At present, the new species is known from IRSNB P 7094 16.5 4.5 5.0 the type locality only. IRSNB P 7095 14.0 4.0 5.0 154
de Teleosteens ACKNOWLEDGEMENTS Huyghebaert, B. & D. Nolf, 1979. Otolithes et
biostratigraphie des Sables de Zonderschot (Miocene Moyen de
la Belgique). — Contr. Tert. Quatern. Geol., 16(2): 59-100, 6 I wish to thank the 'Belgische Vereniging voor Paleontolo- pis. it to the Zonder- gie' for making financially possible expose Marquet, R., 1997. Two Ataxiocerithiumspecies from the Miocene schot Sands Member, Dr R. Marquet (Antwerp) for assistan- of Belgium (Gastropoda Prosobranchia: Cerithiopsidae). — ce in drafting the lithostratigraphic sections and Dr D. Nolf Basteria, 61(1-3): 27-31. (IRSNB) for fruitful discussions and comments. Nolf, D., 1977. Les otolithes de Teleosteens de l'Oligo-Miocene
beige. — Ann. Soc. r. zool. Belg., 106(1)(1976): 3-119,18 pis.
Radwanska, U., 1992. Fish otoliths in the Middle Miocene (Badeni-
an) deposits of southern Poland. — Acta geol. pol., 42(3-4): REFERENCES 141-328, 38 pis.
Sasaki, K., 1989. Phytogeny of the family Sciaenidae,with notes on
Chaine, J., 1938. Recherches sur les otolithes des poissons. Etude its zoogeography(Teleostei, Perciformes). — Mem. Fac. Fish.
descriptive et comparative de la sagitta des Teleosteens V. — Hokkaido Univ., 36(1/2) (no. 53): 1-137. Actes Soc. linn. Bordeaux, 90: 6-258,18 pis. Schwarzhans, W., 1993. A comparative morphological treatise of Chao, L., 1978.A Basis for Western Atlantic Sciaenidae Gassifying recent and fossil otoliths of the family Sciaenidae (Perciformes).
(Teleostei: Perciformes). — NOAA Techn. Rept Circ., 415:1- In: H. Pfeil (ed.). Piscium Catalogus. Otolithi Piscium, 1. Miin- 64. chen 245 (Pfeil): p p. De Meuter, F. & P.G. Laga, 1976. Lithostratigraphy and biostrati- Trewavas, E., 1977. The sciaenid fishes (Croakers or Drums) of the
graphy based on benthonic foraminiferaof the Neogene depo- Indo-West-Pacific. — Trans, zool. Soc. London, 33(4): 253-
sits of northern — Bull. Soc. 133- Belgium. beige Geol., 85(4): 541.
152,1 pi. Weiler, W., 1942. Die Otolithen des rheinischen und nordwestdeut- Hooyberghs, H.J.F., 1980. Note on the stratigraphic position of the schen Tertiars. — Abh. Reichsamts Bodenf., n.F., 206: 1-140, Zonderschot Sands Member of the Berchem Formation (Mioce- 14 pis.
ne, Belgium). — Ann. Soc. geol. Belg., 103: 55-61,1 pi.
Hooyberghs, H.J.F., 1996. Planktonic foraminifera from the Zon-
derschot Sands Member ofthe Berchem Formation (Miocene) Manuscript received 20 June 1997, revised version accepted 1
at Zonderschot, — Tert. Res., 15-25, 4 Belgium. 17(1-2): pis. August 1997.
PLATE 1
P Figs 1-3. Camera-lucida drawings of the holotype (1a, b: IRSNB P 7094) and paratypes (2a, b: IRSNB P 7095 and 3a, b: IRSNB 7096)
Sands Member of‘genus Sciaenidarum’heistensis n. s p., Zonderschot (Berchem Formation, early/middle Miocene), Heist-op-den-
Berg. 155\1
PLATE 1