scholarly journals Trepostome bryozoans buck the trend and ignore calcite-aragonite seas

2021 ◽  
Author(s):  
Marcus M. Key ◽  
Patrick N. Wyse Jackson ◽  
Catherine M. Reid
Keyword(s):  
Type Species ◽  
Late Triassic ◽  
Seawater Chemistry ◽  
Early Ordovician ◽  
Genus Level ◽  
Middle Mississippian

AbstractTrepostome bryozoan skeletalisation did not passively respond to changes in seawater chemistry associated with calcite-aragonite seas. According to Stanley and others, trepostome bryozoans were passive hypercalcifiers. However, if this was the case, we would expect their degree of calcitic colony calcification to have decreased across the Calcite I Sea to the Aragonite II Sea at its transition in the Middle Mississippian. Data from the type species of all 184 trepostome genera from the Early Ordovician to the Late Triassic were utilised to calculate the Bryozoan Skeletal Index (BSI) as a proxy for the degree of calcification. BSI values and genus-level diversity did not decrease across the transition from the Calcite I Sea to the Aragonite II Sea. Nor were there any changes in the number of genus originations and extinctions. This suggests that trepostome bryozoans were not passive hypercalcifiers but active biomineralisers that controlled the mineralogy and robustness of their skeletons regardless of changes in seawater chemistry.

Taxonomic affinities and paleogeography of Stromatomorpha californica Smith, a distinctive Upper Triassic reef-adapted demosponge

2009 ◽  
Vol 83 (5) ◽  
pp. 783-793 ◽  
Author(s):  
B. Senowbari-Daryan ◽  
G. D. Stanley
Keyword(s):  
North America ◽  
Shallow Water ◽  
Type Species ◽  
Upper Triassic ◽  
Northern Calcareous Alps ◽  
Late Triassic ◽  
Separate Species ◽  
Northern Calcareous ◽  
Siliceous Spicules ◽  
Horizontal Layers

Stromatomorpha californica Smith is a massive, calcified, tropical to subtropical organism of the Late Triassic that produced small biostromes and contributed in building some reefs. It comes from the displaced terranes of Cordilleran North America (Eastern Klamath terrane, Alexander terrane, and Wrangellia). This shallow-water organism formed small laminar masses and sometimes patch reefs. It was first referred to the order Spongiomorphidae but was considered to be a coral. Other affinities that have been proposed include hydrozoan, stomatoporoid, sclerosponge, and chambered sponge. Part of the problem was diagenesis that resulted in dissolution of the siliceous spicules and/or replaced them with calcite. Well-preserved dendroclone spicules found during study of newly discovered specimens necessitate an assignment of Stromatomorpha californica to the demosponge order Orchocladina Rauff. Restudy of examples from the Northern Calcareous Alps extends the distribution of this species to the Tethys, where it was an important secondary framework builder in Upper Triassic (Norian-Rhaetian) reef complexes. Revisions of Stromatomorpha californica produce much wider pantropical distribution, mirroring paleogeographic patterns revealed for other tropical Triassic taxa. Review of Liassic material from the Jurassic of Morocco, previously assigned to Stromatomorpha californica Smith var. columnaris Le Maitre, cannot be sustained. Species previously included in Stromatomorpha are: S. stylifera Frech (type species, Rhaetian), S. actinostromoides Boiko (Norian), S. californica Smith (Norian), S. concescui Balters (Ladinian-Carnian), S. pamirica Boiko (Norian), S. rhaetica Kühn (Rhaetian), S. stromatoporoides Frech, and S. tenuiramosa Boiko (Norian). Stromatomorpha rhaetica Kühn described from the Rhaetian of Vorarlberg, Austria shows no major difference from S. californica. An example described as S. oncescui Balters from the Ladinian-Carnian of the Rarau Mountains, Romania, is very similar to S. californica in exhibiting similar spicule types. However, because of the greater distance between individual pillars, horizontal layers, and the older age, S. oncescui is retained as a separate species. The net-like and regular skeleton of Spongiomorpha sanpozanensis Yabe and Sugiyama, from the Upper Triassic of Sambosan (Tosa, Japan), suggests a closer alliance with Stromatomorpha, and this taxon possibly could be the same as S. californica.

A new genus and two new species of planthopper in the tribe Cenchreini (Hemiptera: Auchenorrhyncha: Derbidae) from lowland tropical rainforest in Costa Rica

Zootaxa ◽  
2021 ◽  
Vol 4908 (3) ◽  
pp. 369-392
Author(s):  
BRIAN W. BAHDER ◽  
MARCO A. ZUMBADO ECHAVARRIA ◽  
EDWIN A. BARRANTES BARRANTES ◽  
ERICKA E. HELMICK ◽  
CHARLES R. BARTLETT
Keyword(s):  
New Species ◽  
Costa Rica ◽  
New Taxa ◽  
Type Species ◽  
New Genus ◽  
Additional Data ◽  
New Combination ◽  
Diagnostic Features ◽  
Genus Level ◽  
Two New Species

Recent survey work for planthoppers at La Selva Biological Station in Costa Rica found two new species allied with Cenchrea Westwood. The cytochrome c oxidase subunit I (COI) and 18S were sequenced for the new taxa and used these data to assess the genus-level standing of the new taxa. The new taxa do not cluster with Cenchrea dorsalis Westwood, the type species of Cenchrea. A new genus Tico gen. n. described for the reception of new species described as Tico emmettcarri sp. n. (the type species) and Tico pseudosororius sp. n. Cenchrea sororia Fennah is moved to Tico gen. n., to form the new combination Tico sororius (Fennah). Tico gen. n. is compared with allied genera, and review genus-level diagnostic features and the species composition of Cenchrea, which appears to be compositionally heterogenous, but additional data is needed to evaluate genus-level placement of most species. 

A new genus of ichthyosaur from the Late Triassic Pardonet Formation of British Columbia: bridging the Triassic Jurassic gap

2001 ◽  
Vol 38 (6) ◽  
pp. 983-1002 ◽  
Author(s):  
Elizabeth L Nicholls ◽  
Makoto Manabe
Keyword(s):  
British Columbia ◽  
Type Species ◽  
New Genus ◽  
Late Triassic ◽  
Unique Combination ◽  
Type Specimens ◽  
Nomen Dubium ◽  
The Family ◽  
Large Diamond

Both the genus Shastasaurus and the family Shastasauridae have long been hard to define due to the fragmentary nature of the type specimens. Consequently, recent interpretations of the genus have been based almost entirely on Shastasaurus neoscapularis from the Late Triassic Pardonet Formation of British Columbia. Two new specimens of this taxon, from Pink Mountain, British Columbia, demonstrate that it does not belong in the genus Shastasaurus. This paper describes the new specimens, and refers the species to Metashastasaurus gen nov. Post-cranially, the skeleton of Metashastasaurus resembles that of shastasaurids, differing primarily only in the shape of the scapula and fibula. However, the skull has a unique combination of characters, including large diamond-shaped frontals that enter the supratemporal fenestrae, and very narrow posterior extensions of the nasals, which contact the postfrontals. It also differs from the skull of Shastasaurus in the presence of both a parietal ridge and postparietal shelf. This is a combination of derived characters previously known only in Jurassic forms. The front limb has four proximal carpals and four digits, indicating that previous reconstructions were based on incomplete material. Shastasaurus pacificus Merriam 1895, the type species of the genus Shastasaurus, must be considered a nomen dubium, making the genus Shastasaurus invalid. Until this problem is clarified, the use of the generic name Shastasaurus should be restricted to Merriam's type specimens, of which only Shastasaurus alexandrae and Shastasaurus osmonti are based on adequate material.

Taphonomic bias and the evolutionary history of the family Cidaridae (Echinodermata: Echinoidea)

Paleobiology ◽  
1992 ◽  
Vol 18 (1) ◽  
pp. 50-79 ◽  
Author(s):  
Benjamin J. Greenstein
Keyword(s):  
Type Species ◽  
Evolutionary History ◽  
Middle Triassic ◽  
Upper Jurassic ◽  
Late Triassic ◽  
Type Specimens ◽  
Fossil Material ◽  
Group I ◽  
The Family ◽  
History Of

The class Echinoidea apparently originated during the Ordovician Period and diversified slowly through the Paleozoic Era. The clade then mushroomed in diversity beginning in Late Triassic time and continued expanding into the present. Although this evolutionary history is generally accepted, the taphonomic overprint affecting it has not been explored. To gain a more accurate perception of the evolutionary history of the group, I have compared the diversity history of the family Cidaridae (Echinodermata: Echinoidea) with the preservational style of fossil type species using literature-derived data. The Cidaridae apparently originated in Middle Triassic time and diversified slowly through the Neocomian (Early Cretaceous). Diversity was maintained through the remainder of the Cretaceous and Tertiary Periods, reflecting the diversity history of the subclass. Characterization of the preservational style of type fossil material for the family revealed the following breakdown of preservational states: 60% of species were described on the basis of disarticulated skeletal material, primarily spines; 20% based on intact coronas denuded of spines, apical system, Aristotle's lantern and peristomial plates; 10% based on large coronal fragments; and 10% based on other skeletal elements. This distribution may represent the effect of a disarticulation threshold on the condition of echinoid carcasses before final burial and suggests that preservation of intact specimens may be very unlikely. For cidaroids, previous work has suggested that this threshold is likely to be reached after 7 days of decay.Comparison of the diversity history of the Cidaridae with the preservation data reveals that characteristic patterns of taphonomic overprint have affected the group since its origination in Middle Triassic time, and the nature of that overprint has changed over time: the early diversity history of the group is characterized by occurrences of fragmented fossil material, with spines predominant; further radiation of the group in mid-Jurassic time coincided with an increase in modes of preservation, ranging between exceptionally well-preserved material and disarticulated skeletal elements. Finally, type material is more rarely described from younger stratigraphic intervals (Miocene–Pleistocene) and consists predominantly of disarticulated skeletal elements and coronal fragments larger than an interambulacrum in size. Intact, denuded coronas are noticeably lacking.The number of type species of Cidaridae described in each stratigraphic interval has not been consistent during post-Paleozoic time. Middle Triassic, Malm (Upper Jurassic), Senonian (Upper Cretaceous) and Eocene series yielded significantly (α = .05) higher numbers of type specimens per million years, while the Lias (Lower Jurassic), Dogger (Mid-Jurassic), Lower Cretaceous and Paleocene yielded significantly (α = .05) lower numbers of type specimens per million years. This may be the result of a combination of taxonomic, sampling, and geographical biases.

Upper Triassic corals from Nevada, western North America, and the implications for paleoecology and paleogeography

2013 ◽  
Vol 87 (5) ◽  
pp. 934-964 ◽  
Author(s):  
Ewa Roniewicz ◽  
George D. Stanley
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Upper Triassic ◽  
Late Triassic ◽  
Western North America ◽  
North American Cordillera ◽  
Coral Fauna ◽  
Taxonomic Analysis ◽  
The North

Late Carnian–early Norian corals from the Luning and Osobb formations in west-central Nevada represent an important Late Triassic fauna for understanding the paleoecology and the paleogeography of the eastern Panthalassa region during Late Triassic time. The corals occur in bedded limestone representing biostromes and patch reefs and their composition presages the important global changeover of faunas of the intra-Norian interval. A taxonomic analysis of over 60 specimens reveals a majority of colonial corals ranging from cerioid, astreoid (i.e., cerioid-plocoid lacking walls), meandroid and thamnasterioid types. Surprisingly, remnants of the original aragonite microstructure remain in some specimens, allowing a better comparison with more remote Tethyan corals. In total, 14 genera have been identified from Nevada while two genera remain undetermined. The fauna is composed of species considered typical of both the North American Cordillera and cratonal South America. The following genera and species are new and endemic to the Americas:Khytrastrea silberlingiandK. cuifiamorpha,Flexastrea serialis,Nevadoseris punctata,Areaseris nevadaensisand a new genusMinasteria(withAstrocoenia shastensisSmith, 1927 as type species). Likewise are the new species:Margarogyra silberlingiandCurtoseris dunlapcanyonae. GeneraMeandrovolzeia,Margarogyra,Ceriostella,Ampakabastraea,Retiophyllia,Distichomeandra,Curtoseris,ThamnasteriaandAstraeomorphaprovide important links to the former Tethys province. The revised coral fauna changes previous views of the close taxonomic similarity with the Tethys, instead producing a paleogeographic pattern emphasizing a much greater degree of endemism. This pattern emphasizes the isolation of Nevada from the Tethys and the similarities with some outboard terranes of the Cordillera.

scholarly journals A Review of Necrotauliids from the Triassic/Jurassic of England (Trichoptera: Necrotauliidae)

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Richard S. Kelly ◽  
Andrew J. Ross ◽  
Robert A. Coram
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Type Locality ◽  
Late Triassic ◽  
Type Specimens ◽  
The Family ◽  
The Uk ◽  
A New Species ◽  
Paraphyletic Assemblage

Species previously attributed to Necrotauliidae are revised from the Late Triassic and Early Jurassic of England based on examination of type specimens and non-type material. The necrotauliids have been considered as a basal family of caddisflies (Trichoptera) or as a paraphyletic assemblage of stem-amphiesmenopterans. Herein a new genus, Austaulius, is erected which includes all Lilstock Formation∖Lower Lias material from England; the previously described species are synonymized with A. furcatus and a new species, A. haustrum, is described from the Dorset Coast, the holotype of which preserves synapomorphic traits of the Trichoptera not previously described suggesting that the family is trichopteran. The type genus remains Necrotaulius and type species N. parvulus (Geinitz, 1884) from the type locality of Dobbertin, Germany. One species of Necrotaulius is represented in the UK, N. parvulus, which is found in the Upper Lias.

The taxonomic status of the phytosaurs (Archosauriformes) Machaeroprosopus and Pseudopalatus from the Late Triassic of the western United States

2012 ◽  
Vol 103 (3-4) ◽  
pp. 265-268 ◽  
Author(s):  
William G. Parker ◽  
Axel Hungerbühler ◽  
Jeffrey W. Martz
Keyword(s):  
Type Species ◽  
Historical Context ◽  
Taxonomic Status ◽  
Type Specimen ◽  
Western United States ◽  
Late Triassic ◽  
Zoological Nomenclature ◽  
Nominal Species ◽  
International Code ◽  
Primary Literature

ABSTRACTThe genus Machaeroprosopus has long been considered invalid because the type specimen of the Late Triassic phytosaur species, M. validus, has been lost. Re-examination of the primary literature regarding the establishment of the Late Triassic phytosaur genus Machaeroprosopus demonstrates that M. buceros is the correct type species, not M. validus. Thus, the genus level name Machaeroprosopus has priority over the genera Pseudopalatus and Arribasuchus and all nominal species should be reassigned. Reassignment of these species to Machaeroprosopus satisfies the requirements of the International Code of Zoological Nomenclature (ICZN) and preserves historical context. The name Pseudopalatinae is retained as the valid clade name for these phytosaurs because its usage falls outside of the ICZN.

scholarly journals A revision of the early neotheropod genus Sarcosaurus from the Early Jurassic (Hettangian–Sinemurian) of central England

2020 ◽  
Vol 191 (1) ◽  
pp. 113-149 ◽  
Author(s):  
Martín D Ezcurra ◽  
Richard J Butler ◽  
Susannah C R Maidment ◽  
Ivan J Sansom ◽  
Luke E Meade ◽  
...  
Keyword(s):  
Type Species ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Valid Species ◽  
Character State ◽  
New Information ◽  
Evolutionary Radiation ◽  
Nomina Dubia

Abstract Neotheropoda represents the main evolutionary radiation of predatory dinosaurs and its oldest records come from Upper Triassic rocks (c. 219 Mya). The Early Jurassic record of Neotheropoda is taxonomically richer and geographically more widespread than that of the Late Triassic. The Lower Jurassic (upper Hettangian–lower Sinemurian) rocks of central England have yielded three neotheropod specimens that have been assigned to two species within the genus Sarcosaurus, S. woodi (type species) and S. andrewsi. These species have received little attention in discussions of the early evolution of Neotheropoda and recently have been considered as nomina dubia. Here, we provide a detailed redescription of one of these specimens (WARMS G667–690) and reassess the taxonomy and phylogenetic relationships of the genus Sarcosaurus. We propose that the three neotheropod specimens from the Early Jurassic of central England represent a single valid species, S. woodi. The second species of the genus, ‘S. andrewsi’, is a subjective junior synonym of the former. A quantitative phylogenetic analysis of early theropods recovered S. woodi as one of the closest sister-taxa to Averostra and provides new information on the sequence of character state transformations in the lead up to the phylogenetic split between Ceratosauria and Tetanurae.

Late Triassic megalodontids (Bivalvia) from the headwaters of the Yangtze River, Qinghai province, west China

2007 ◽  
Vol 81 (6) ◽  
pp. 1327-1347 ◽  
Author(s):  
Huazhou Yao ◽  
Renjie Zhang ◽  
John Pojeta ◽  
Jinggen Sha ◽  
Jianxiong Wang
Keyword(s):  
New Species ◽  
Yangtze River ◽  
Type Species ◽  
Upper Triassic ◽  
Late Triassic ◽  
The Yangtze River ◽  
External Appearance ◽  
West China ◽  
Qinghai Province

A bivalve faunule of six species is described from the Upper Triassic Jiapila Formation at the headwaters of the Yangtze River, southern Qinghai, China. The new species, Neomegalodon cornutus and Quemocuomegalodon circularis, are described. The type species of Quemocuomegalodon, Q. orientus, is revised. Quemocuomegalodon orientus Yao, Sha, and Zhang (2003) is now known from abundant, well-preserved specimens that show great variation in shape, size, thickness of shell, and dentition, and the species Q. longitatus, Yao, Sha, and Zhang (2003) is now placed in synonymy with Q. orientus. There are significant morphologic differences between the external appearance of shelled specimens and the internal molds of species of Quemocuomegalodon. This suggests the need for the re-evaluation of many megalodontid species from elsewhere that are known only from internal molds.

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