Hecticoceras puteale
| Hecticoceras puteale | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Middle Jurassic (Upper Callovian ) | ||||||||||||
| 163.5 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Hecticoceras puteale | ||||||||||||
| ( Leckenby , 1859) | ||||||||||||
Hecticoceras puteale is a species of the ammonites (Ammonoidea) from the Jura . As macroconches, the animals had a wide-naveled casing with strong ribs and a simple mouth, and as microconches they had bubble-shaped tubercles. The maximum diameter of the species was around 6 cm. The known distribution extended over the area of south-eastern Great Britain, which was then covered by a tributary sea of the Tethys . The species was first described in 1859 by John Leckenby .
features
Hecticoceras puteale had a slightly wide-naveled casing on the macroconch, which had thick turns and a relatively strong ribbing. The rounded ribs show a club-like thickening towards the outer bend. The secondary ribs disappear towards the sharp keel of the external side of the housing. The macroconch mouth is simple in shape. With a total diameter of 60 mm, the animals were probably fully grown. The microconch of the species was more naveled, high-mouthed and provided with muzzle ears. As a rule, the ribs on the inner flank halves were transformed into bubble-shaped tubercles, from which fine secondary ribs extend on the outer bend. The external side of the microconch was simply keeled, the opening was provided with muzzle ears. When fully grown, the smaller animals were probably less than 30 mm in diameter.
Stratigraphy and geographic distribution
Hecticoceras pseudopunctatum occurs in the lamberti zone of the British Jura. It is particularly common there in the Lamberti sub-zone, i.e. the uppermost section of the Callovian at the transition to the Upper Jurassic . The distribution extended over the area of today's southeastern Great Britain.
Taxonomy and systematics
The species was in 1859 by John Leckenby from Hackness rock member of the Oxford Clay as "Ammonites putealis" first described . Hecticoceras puteale is placed within Hecticoceras in the subgenus Putealiceras , of which it is a type species . The representatives of this group are characterized by thick turns and strong ribbing on the macroconches and a keeled external side.
literature
- John Leckenby: On the Kelloway Rock of the Yorkshire Coast . In: Quarterly Journal of the Geological Society . tape 15 , no. 1-2 , 1859, ISSN 0370-291X , p. 4–15 , doi : 10.1144 / GSL.JGS.1859.015.01-02.07 (English).
- Kevin N. Page: Ammonites. In: David M. Martill, John D. Hudson (Eds.): Fossils from Ornatenton and Oxford Clay . A determination atlas. Goldschneck-Verlag, Korb 1994, ISBN 3-926129-17-4 , pp. 117-149.
- Arnold Zeiss: Hecticoceratinae (Ammonoidea jurassica) (= Fossilium Catalogus. 1: Animalia. Ps. 96, ZDB -ID 1187037-0 ). Junk, 's-Gravenhage 1959.