Revision of Cyclida (Pancrustacea, Multicrustacea), with five new genera

2020 ◽  
Vol 296 (3) ◽  
pp. 245-303
Author(s):  
Carrie E. Schweitzer ◽  
Eduard V. Mychko ◽  
Rodney M. Feldmann
Keyword(s):  
Mass Extinction ◽  
New Genus ◽  
New Combinations ◽  
New Genera ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction ◽  
Freshwater Environments

All cyclidan species represented by existing material are illustrated photographically. New genera within Cyclidae include Ambocyclus new genus; Carabicyclus new genus; Chernyshevine new genus, Litocyclus new genus; and Tazawacyclus new genus with the following new combinations: A. capidulum (Chernyschev, 1933); A. simulans (Reed, 1908); A. ? minutus (Rogers, 1902); Carabicyclus wrighti (Woodward, 1870); L. bilobatus (Woodward, 1870); L. ? communis (Rogers, 1902); L. jonesianus (Woodward, 1870); L. ? permarginatus (Rogers, 1902); L. torosus (Woodward, 1870); Chernyshevine spinosus (Chernyschev, 1933); T. tazawai (Niko & Ibaraki, 2011); U. harknessi (Woodward, 1870); and U. woodwardi (Reed, 1893). New genera within Americlidae include Brittaniclus and Dziklus with the following new combinations: B. rankini (Woodward, 1868); B. scotti (Woodward, 1894); B. testudo (Peach, 1882); and D. obesus (Schram, Vonk & Hof, 1997). A neotype is herein designated for Halicyne plana. Each family within Cyclida occupies a distinct morphospace. Two families survived the end-Permian mass extinction event. Most cyclidans occupied marine conditions, but some are known from marginal marine and freshwater environments.

Paleocene diversification of bucciniform gastropods on Seymour Island, Antarctica

1996 ◽  
Vol 70 (6) ◽  
pp. 923-934 ◽  
Author(s):  
Anton E. Oleinik ◽  
William J. Zinsmeister
Keyword(s):  
New Species ◽  
Mass Extinction ◽  
Fossil Record ◽  
New Genus ◽  
Shell Morphology ◽  
Geographic Isolation ◽  
Extinction Event ◽  
Early Paleocene ◽  
Mass Extinction Event ◽  
Seymour Island

Following the mass extinction event at the end of the Cretaceous, the marine molluscan faunas of the high southern latitudes underwent a marked period of diversification during the early Paleocene. The appearance of four new species belonging to the new genus Seymourosphaera, tentatively placed in the subfamily Pseudolivinae, from the lower Paleocene strata of Seymour Island, Antarctic Peninsula, clearly illustrates the post-Cretaceous extinction diversification. The abrupt radiation of the buccinids during the early Paleocene, was also apparently related to geographic isolation of Antarctica during final breakup of Gondwana. Comparative analysis of shell morphology of Seymourosphaera, new genus reveals close morphologic similarities, not only with taxa within Pseudolivinae, but also with several genera and subgenera belonging to the families Buccinidae and Nassariidae. However, incompleteness of the fossil record and a “generalized” shell morphology make difficult establishment of unequivocal phylogenetic relationships for Seymourosphaera. A taxonomic review of most closely related, and possibly ancestral genus Austrosphaera Camacho, 1949, is provided. The following new species of genus Seymourosphaera new genus are described: Seymourosphaera bulloides new species, S. subglobosa new species, S. depressa new species, and S. elevata new species.

scholarly journals Subsequent biotic crises delayed marine recovery following the late Permian mass extinction event in northern Italy

PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0172321 ◽  
Author(s):  
William J. Foster ◽  
Silvia Danise ◽  
Gregory D. Price ◽  
Richard J. Twitchett
Keyword(s):  
Mass Extinction ◽  
Northern Italy ◽  
Late Permian ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction

Rapid marine recovery after the end-Permian mass-extinction event in the absence of marine anoxia

Geology ◽  
2004 ◽  
Vol 32 (9) ◽  
pp. 805 ◽  
Author(s):  
R.J. Twitchett ◽  
L. Krystyn ◽  
A. Baud ◽  
J.R. Wheeley ◽  
S. Richoz
Keyword(s):  
Mass Extinction ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction

Changhsingian conodont succession and the end-Permian mass extinction event at the Daijiagou section in Chongqing, Southwest China

2015 ◽  
Vol 105 ◽  
pp. 234-251 ◽  
Author(s):  
Dong-xun Yuan ◽  
Jun Chen ◽  
Yi-chun Zhang ◽  
Quan-feng Zheng ◽  
Shu-zhong Shen
Keyword(s):  
Mass Extinction ◽  
Southwest China ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction

Earliest Silurian faunal survival and recovery after the end Ordovician glaciation: evidence from the brachiopods

2007 ◽  
Vol 98 (3-4) ◽  
pp. 291-301 ◽  
Author(s):  
L. Robin M. Cocks ◽  
Rong Jia-yu
Keyword(s):  
Global Warming ◽  
Recovery Rate ◽  
Mass Extinction ◽  
Ice Age ◽  
Benthic Assemblages ◽  
Ice Cap ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction ◽  
Ecological Recovery

ABSTRACTEarliest Silurian (basal Llandovery) brachiopod faunas are surveyed and listed from around the globe, and divided between Lower Rhuddanian and Upper Rhuddanian occurrences. 60 genera are known from the Lower Rhuddanian within 20 superfamilies and there are 87 genera in 25 superfamilies in the Upper Rhuddanian. The 29 areas surveyed span the globe, both latitudinally and longitudinally. Only six superfamilies are Lazarus taxa which are known both from the Ordovician and Middle Llandovery (Aeronian) and later rocks but have not been recorded from the Rhuddanian. These are surprising results, since many previous studies have inferred that the Rhuddanian was a time of very sparse faunas. The global warming that followed the latest Ordovician (Hirnantian) ice age did not proceed quickly, with an ice-cap probably present through at least the Llandovery. There is a marked absence of Lower Rhuddanian bioherms even at low palaeolatitudes; however, the ecological recovery rate was far faster than that following the end-Permian mass extinction event. The partitioning of the Rhuddanian shelf faunas into well-defined benthic assemblages progressed slowly over the interval.

scholarly journals The main stage of recovery after the end-Permian mass extinction: taxonomic rediversification and ecologic reorganization of marine level-bottom communities during the Middle Triassic

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11654
Author(s):  
Evelyn Friesenbichler ◽  
Michael Hautmann ◽  
Hugo Bucher
Keyword(s):  
Mass Extinction ◽  
Middle Triassic ◽  
Biotic Interactions ◽  
Trophic Relationships ◽  
Lag Phase ◽  
Early Triassic ◽  
Bottom Communities ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
Permian Mass Extinction

The recovery of marine life from the end-Permian mass extinction event provides a test-case for biodiversification models in general, but few studies have addressed this episode in its full length and ecological context. This study analyses the recovery of marine level-bottom communities from the end-Permian mass extinction event over a period of 15 Ma, with a main focus on the previously neglected main phase during the Middle Triassic. Our analyses are based on faunas from 37 lithological units representing different environmental settings, ranging from lagoons to inner, mid- and outer ramps. Our dataset comprises 1562 species, which belong to 13 higher taxa and 12 ecological guilds. The diversification pattern of most taxa and guilds shows an initial Early Triassic lag phase that is followed by a hyperbolic diversity increase during the Bithynian (early middle Anisian) and became damped later in the Middle Triassic. The hyperbolic diversity increase is not predicted by models that suggest environmental causes for the initial lag phase. We therefore advocate a model in which diversification is primarily driven by the intensity of biotic interactions. Accordingly, the Early Triassic lag phase represents the time when the reduced species richness in the wake of the end-Permian mass extinction was insufficient for stimulating major diversifications, whereas the Anisian main diversification event started when self-accelerating processes became effective and stopped when niche-crowding prevented further diversification. Biotic interactions that might drive this pattern include interspecific competition but also habitat construction, ecosystem engineering and new options for trophic relationships. The latter factors are discussed in the context of the resurgence of large carbonate platforms, which occurred simultaneously with the diversification of benthic communities. These did not only provide new hardground habitats for a variety of epifaunal taxa, but also new options for grazing gastropods that supposedly fed from microalgae growing on dasycladaceans and other macroalgae. Whereas we do not claim that changing environmental conditions were generally unimportant for the recovery of marine level-bottom communities, we note that their actual role can only be assessed when tested against predictions of the biotic model.

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