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From time to time, I would like to post specimens from the Campanian St. Bartholomä-formation in Styria, Austria, in this thread. For the first specimen, I was motivated by this thread: http://www.thefossilforum.com/index.php?/topic/91459-is-this-a-rudist-fossil/ So the first specimen is a fragment of a large Vaccinites alpinus, with only two pillars - and not much else. Franz Bernhard
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Fossil hunting in the Geistthal-formation (Santonian - lower Campanian), Gosau basin of Kainach, Styria, Austria
FranzBernhard posted a topic in Fossil Hunting Trips
Fossil hunting in the Santonian - lower Campanian Geistthal-formation of the Gosau basin of Kainach, Eastern Alps (Styria, Austria) As a whole, the Gosau basin of Kainach - St. Bartholomä is not very fossiliferous. In contrast to the St. Bartholomä-formation with its rudists etc., the other, much more extensive formations, especially the very extensive, somewhat tubititic Afling-formation, are generally very poor in fossils. Some are known, eg. ammonites, but their occurrences are rather elusive. One exception - or at least in part - are Trochactaeon snails. They are known since the beginning of geological documentation of the area (around 1850), but only as loose pieces. It took until about the 1960ies for the first finds of this snails in outcrops. However, only a few sentences were (repeatedly) published since then, only a list of the species is given (without any description), and also no detailed description of the occurrences and their exact locations. That´s the sad side. The good side is: There is at least one (permanent) occurrence of this snails in an outcrop at a major road! This occurrence is at the red X... Part of Geofast-map (left, squares are 2x2 km) and geological overview from Ebner (2000) (right). There seems to be not much correspondence between these maps. For orientation, see village Geistthal in upper part of both maps. ...and it is featured in an excursion guide from 2015 (from Hubmann & Gross, 2015): The snails are located in the upper part of the Geistthal-formation, a succession of gray conglomerates, sandstones and siltstones with very occasional thin coal layers and thin beds of calcareous onkoids. The lower part of the Geistthal-formation is a coarse-grained, red conglomerate; its the basal formation of the Gosau basin of Kainach. I have visited this outcrop in December 2015, and yes, the snails are still there. -
Apical view of a polished cross section of the right (lower) valve of Hippurites nabresinensis from the St. Bartholomä-Formation of the Gosau basin of Kainach - St. Bartholomä in western Styria, Austria. This species has no L-pillar, the P1-pillar is at ca. 3:00, the P2-pillar at ca. 5:00. The hump at ca. 8:00 is a growth anomaly. At ca. 11:00 and 1:00, the position of both teeth sockets is visible (a hypothetical L-pillar would be between them, see the specimen of H. colliciatus), at ca. 2:00 the position of the posterior muscle. At the upper left, it is intergrown with the fragment of another individual of the same (?) species. For specimens like this, the name H. heritschi was also in use. The specimen is from a large mound of stones, which were removed from the fields during many, many decades. This mound located in the southwerstern part of Kalchberg, southwest of St. Bartholomä (Point 36 in my own documentation).
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Apical view of a polished cross section of the right (lower) valve of Vaccinites alpinus from the St. Bartholomä Formation of the Gosau basin of Kainach - St. Bartholomä in western Styria, Austria. Typical are the subparallel pillars, all situated in a small area of the rudist. The shell around the L-piller (left one) is missing in this specimen. For specimens like this, the name Hippurites/Vaccinites cornuvaccinum was in use. Study of specimens with preserved upper valve showed that V. cornuvaccinum is restricted to the Coniacian and V. alpinus to the upper Santonian and Campanian (Steuber & Schlüter, 2012). They can not be distinguished with the lower valve alone, but have different upper valves. Hence, identification is (also) based on stratigraphic information (Steuber, 2001: „This species [V. ultimus] was also figured by Kaumanns (1962) from Kainach (Styria) and erroneously assigned to various species of the group of V. cornuvaccinum.“). By the way, V. ultimus is a junior synonym of V. alpinus... (Steuber, 2003). The specimen is from a small scree in a small, abandoned marl quarry, located in the eastern part of Kalchberg, southwest of St. Bartholomä (Point 25 in my own documentation).
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Apical view of a polished cross section of the right (lower) valve of Vaccinites vesiculosus from the St. Bartholomä-Formation of the Gosau basin of Kainach - St. Bartholomä in western Styria, Austria. Typical are the slender L-pillar (at ca. 12:00), the round P1-pillar with a very slender stem (at ca. 2:00) and the spatula-shaped P2-piller, also with very slender steem (at ca. 3:00). For specimens like this, names like Hippurites styriacus und Hippurites carinthiacus were also in use. The specimen is from a small scree in a small, abandoned marl quarry, located in the eastern part of Kalchberg, southwest of St. Bartholomä (Point 25 in my own documentation).