Triassic clam shrimps (“Conchostraca”; Branchiopoda: Diplostraca) from Mallorca: Taxonomic description and interregional comparisons

Zootaxa ◽  
2021 ◽  
Vol 4964 (3) ◽  
pp. 471-496
Author(s):  
FRANK SCHOLZE ◽  
RAFEL MATAMALES-ANDREU
Keyword(s):  
Middle Triassic ◽  
Lower Triassic ◽  
Western Mediterranean ◽  
Central European ◽  
Valve Morphology ◽  
Central European Basin ◽  
Taxonomic Description ◽  
Clam Shrimp ◽  
Original Definition ◽  
German Part

We describe four upper Lower Triassic to lower Middle Triassic clam shrimp-bearing intervals from Mallorca, which include the clam shrimp species Hornestheria sp. aff. Hornestheria sollingensis and several other forms of carapace valve morphology: Hornestheria? Morphotype 1, Hornestheria? Morphotype 2, and other undetermined carapace valves. All of this material was obtained from red-bed units cropping out in the Serra de Tramuntana mountains of Mallorca (western Mediterranean). Except for a few morphologically similar carapace valves of Middle Triassic age from China, Hornestheria is known only from the type locality of its type species, Hornestheria sollingensis Kozur et Lepper, in the Solling Formation (Middle Buntsandstein Subgroup) in the German part of the Central European Basin. According to its original definition, the larval carapace valve of Hornestheria Kozur et Lepper is characterized by a radial sculpture, but this characteristic apparently is only variably developed. Due to both a limited number of previously known occurrences of Hornestheria and its poorly known carapace valve morphology, open nomenclature is applied to the taxonomy herein. The studied specimens were freshly collected from outcrop sections composed of greyish-green to greyish-red laminated claystones and siltstones that accumulated in a fluvial facies. The clam shrimp specimens are accompanied by remains of insects and fishes, invertebrate and tetrapod ichnofossils, and micro-/macroplant remains, all of which either have been described by previous workers or are currently part of a separate study. 

The Permian–Triassic boundary in continental sedimentary succession at the SE margin of the Central European Basin (Holy Cross Mountains, Poland)

2020 ◽  
Vol 157 (11) ◽  
pp. 1767-1780
Author(s):  
Karol Jewuła ◽  
Wiesław Trela ◽  
Anna Fijałkowska-Mader
Keyword(s):  
Lower Triassic ◽  
Upper Permian ◽  
Triassic Boundary ◽  
Central European ◽  
Holy Cross Mountains ◽  
Central European Basin ◽  
Stratigraphic Framework ◽  
Marginal Part ◽  
Permian Triassic Boundary ◽  
Shed Light

AbstractWe studied the upper Permian and Lower Triassic deposits from the northern and northwestern marginal part of the Holy Cross Mountains (SE part of the Central European Basin or CEB, Poland) to examine stratigraphic continuity between these two systems, and to revise the currently existing stratigraphic framework. A previously existing informal lithostratigraphic scheme has been revisited and placed in a broader chronostratigraphic and palaeoenvironmental context. Sedimentary continuity across the Permian–Triassic (P/T) boundary has been confirmed by the presence of Lueckisporites virkkiae Bc morphological norm and Lundbladispora obsoleta–Protohaploxypinus pantii palynomorphs. Facies development reflects an interplay between climatic variations and tectonism during late Permian – Early Triassic time. The P/T boundary was placed between the Siodła Formation and overlying Szczukowice and Jaworzna formations, which coincides with the classical Zechstein–Buntsandstein boundary in the SE part of the CEB. The facies changes recorded in the studied terrestrial succession of the P/T boundary shed light on the environmental dynamic prior, during and after one of the biggest biotic crises in Earth’s history.

Helmolepis cyphognathus, sp. nov., a new platysiagid actinopterygian from the Lower Triassic Sulphur Mountain Formation (British Columbia, Canada)

2005 ◽  
Vol 42 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Andrew G Neuman ◽  
Raoul J Mutter
Keyword(s):  
British Columbia ◽  
New Species ◽  
Central Europe ◽  
Middle Triassic ◽  
Lower Triassic ◽  
Western Canada ◽  
Early Triassic ◽  
East Greenland ◽  
The Family ◽  
A New Species

A new species of stem actinopterygian, Helmolepis cyphognatus sp. nov., is reported from the Lower Triassic Sulphur Mountain Formation of western Canada (probably Smithian). This taxon differs from the only other known Early Triassic platysiagid, H. gracilis from the Lower Triassic Wordie Creek Formation of East Greenland (Griesbachian), in counts of branchiostegal rays, shape of the maxilla, shape (and possibly counts) of extrascapulars, and the size ratio of major opercular bones. In spite of their overall unfavorable preservation, the numerous available specimens amend our knowledge of the little known genus Helmolepis considerably: it has become evident that the morphology of Helmolepis cyphognatus sp. nov. comes closest to Platysiagum minus (Middle Triassic Besano Formation of central Europe). This study suggests placement of the two genera in the family Platysiagidae. Investigation of this new species also shows certain features of the cheek and the caudal fin are more primitive than previously believed, whereas the snout region is probably derived but of yet uncertain affinities in Helmolepis.

On the presence ofMixosaurus(Ichthyopterygia: Reptilia) in the Middle Triassic of Nevada

1990 ◽  
Vol 64 (1) ◽  
pp. 161-164 ◽  
Author(s):  
P. Martin Sander ◽  
Hugo Bucher
Keyword(s):  
British Columbia ◽  
North America ◽  
Middle Triassic ◽  
Lower Triassic ◽  
High Arctic ◽  
Western Tethys ◽  
History Of ◽  
Northwestern North America

The small ichthyosaurMixosaurusis the most widely distributed ichthyosaur. It is known from Lower Triassic rocks of British Columbia, Canada (Callaway and Brinkman, 1989), and Middle Triassic rocks of northwestern North America (Alaska, British Columbia), China, Timor, the western Tethys (Switzerland, Italy, Turkey), the Germanic Triassic, and the high Arctic (Spitsbergen, Exmouth Island) (Mazin, 1986; Callaway and Brinkman, 1989; Callaway and Massare, 1989). The presence ofMixosaurusin one of the richest ichthyosaur provinces, the Middle Triassic of Nevada (Merriam, 1908), has been difficult to establish. The history of this problem is very colorful and is the topic of this note together with the description of a new specimen from the Nevada Middle Triassic.

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