Uptonia

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Uptonia
Uptonia jamesoni

Uptonia jamesoni

Temporal occurrence
Pliensbachium
189.6 to 183.0 million years
Locations
Systematics
Cephalopods (cephalopoda)
Ammonites (ammonoidea)
Ammonitida
Eoderoceratoidea
Polymorphitidae
Uptonia
Scientific name
Uptonia
Buckman

Uptonia is a genus of medium-sized, evolutionary, ribbed ammonites . It occursquite widelyas a key fossil in the lower Pliensbachian ( Carixian ).

description

Some individuals of the genus Uptonia sometimes reach a quite stately size of up to 30 centimeters, but average values are 10 centimeters. Its phragmocone is evolute (with N = 0.45), somewhat compressed and has simple, rounded ribs without tubercles. Young forms up to a diameter of 5 centimeters are, however, reinforced with tubercles on their flanks towards the venter. The ribs bend forward on the ventral side, depending on the taxon to a different extent. The umbilical is very deep. The winding cross-section is elliptical to rounded, but appears almost square in the youth stage. The complicated praising line with its large side praises is typical of neoammonites.

Way of life

The individuals of the genus Uptonia were marine carnivores that populated the shallow as well as the deeper calcareous subtidal from the transition zone to the deeper beach area .

Systematics

The genus Uptonia belongs to the family of Polymorphitidae Haug , 1887 (subfamily Polymorphitinae Haug, 1887 ) within the superfamily of Eoderoceratoidea Spath , 1929 . The following taxa are known from her:

Gemmellaroceras , Jamesonites , Parinodiceras , Platypleuroceras and Polymorphites act as sister taxa .

Ammonite zone

The genus Uptonia is a key fossil and defines the first ammonite zone of the Pliensbachian, the Jamesoni zone . The Jamesoni zone follows the Raricostatum zone of the Sinemurian and is in turn overlaid by the Ibex zone .

The Jamesoni zone, named after Uptonia jamesoni , is made up of four sub-zones, the Taylori sub-zone in the horizontal , followed by the Polymorphus sub-zone, the Brevispina sub-zone and the Jamesoni sub-zone in the hanging wall . The Jamesoni subzone is further divided into the Jamesoni biozone and above that the Pettos biozone. The Jamesoni biozone consists of the sole horizon of Uptonia jamesoni paired with Uptonia bronni , the Pettos biozone consists of the horizon of Uptonia lata paired with Uptonia bronni and above that the horizon of Uptonia sp. . Uptonia sp. extends into the first horizon of the adjoining Ibex zone.

In the Tethyan Mittelmeerproinz (Alpine Space, Spain) the species occurs Uptonia not on, but is replaced by other Ammonitentaxa.

Occurrence

The genus Uptonia appears in Germany in the southern German Lias on the Swabian Alb near Pliensbach , but also near Karlsruhe (near Östringen ) in Baden-Württemberg as well as near Beierstedt in Lower Saxony and near Herford in North Rhine-Westphalia . In Austria , the Adnet formation in the state of Salzburg should be mentioned, with find points at Adnet and on the Rotkogel near Bad Ischl . In Hungary it occurs in the lower Lias of the Bakony Mountains .

The Mont Lachat de Châtillon, Jura cliff and Uptonia site

There are numerous sites in France , for example in the Ariège department , in the Calvados department ( Fresnay-le-Puceux , Basse-Normandie), in the Cher department , in the Western Alps in the Haute-Savoie department ( Mont Lachat de Châtillon ) and in the Isère department ( Oisans ), in the Vendée department and in the Carixium der Causses near Rivière-sur-Tarn and near Saint-Georges-de-Luzençon . In England , Uptonia performs in the Belemnite Marls Formation at Charmouth in Dorset . Finds in Northern Ireland are in County Antrim at Collin Glen and Portrush .

literature

  • WJ Arkell et al .: Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology. Geological Society of America and University of Kansas Press, 1957.
  • RC Moore: Treatise on Invertebrate Paleontology. Part L. Mollusca 4. Ammonoidea. Geological Society of America, 1957, pp. 248 .
  • Kevin N. Page: The Lower Jurassic of Europe: its subdivision and correlation . In: Geological Survey of Denmark and Greenland Bulletin . tape 1 , 2003, p. 23-59 .
  • Rudolf Schlegelmilch: The ammonites of the southern German Lias: an identification book for fossil collectors and geologists. - 2nd edition Gustav Fischer Verlag, Stuttgart, Jena, New York 1992, p. 241 .

Individual evidence

  1. ↑ JJ Sepkoski: A compendium of fossil marine animal genera . In: Bulletins of American Paleontology . tape 363 , 2002, p. 1-560 .
  2. ^ G. Arp and S. Seppelt: The bipolar bivalve Oxytoma (Palmoxytoma) cygnipes (Young and Bird, 1822) in the Upper Pliensbachian of Germany . In: Palaeontological Journal . tape 86 , 2012, p. 43-57 .
  3. ^ Christian Meister and Florian Böhm: Austroalpine Liassic Ammonites from the Adnet Formation (Northern Calcareous Alps) . In: Yearbook of the Federal Geological Institute . tape 136 , 1993, ISSN  0016-7800 , pp. 163-211 .
  4. ↑ B. and C. Geczy Master: Les ammonites you Sinémurien du et Pliensbachien inférieur de la montagne du Bakony (Hongrie) . In: Revue de Paléobiologie . tape 26 (1) , 2007, pp. 137-305 .
  5. ↑ J.- L. Dommergues et al .: Les ammonites du Pliensbachien et du Toarcien basal dans la carrière de la Roche Blain (Fresnay-le-Puceux, Calvados, Basse-Normandie, France). Taxonomy, implications stratigraphiques et paleobiogéographiques . In: Revue de Paléobiologie . Muséum d'Histoire Naturelle de la ville de Genève 2008, p. 277 .
  6. ^ René Mouterde and Jean Rosset: La nappe supérieure des klippes de Savoie - Stratigraphie du Rhétien et du Lias . In: Trav. Lab. Géol. Grenoble . t. 43, 1967, p. 129-137 .
  7. ↑ P. Fauré and P. Bohain: Les ammonites du Pliensbachien inférieur de la Vendée méridionale (France) - Etude taxonomique. Implications stratigraphiques et paleogéographiques . In: STRATA . volume 54. Laboratoire de Géologie sédimentaire et Paléontologie, Université Paul-Sabatier, Toulouse, France 2017, p. 74 .
  8. ^ Christian Meister: Les ammonites du Carixien des Causses (France) . In: Swiss palaeontological treatises . tape 109 , 1986, pp. 1-209 .
  9. ^ WD Lang, LF Spath, LR Cox and HM Muir-Wood: The Belemnite marls of Charmouth, a series in the Lias of the Dorset Coast . In: Quarterly Journal of the Geological Society . tape 84 , 1928, pp. 179-257 .