{"title":"A Middle Triassic Cassian‐type fauna (Pelsa‐Vazzoler Lagerstätte) and the adaptive radiation of the Modern evolutionary fauna","authors":"Stefano Dominici, Silvia Danise, Andrea Tintori","doi":"10.1002/spp2.1579","DOIUrl":null,"url":null,"abstract":"We describe a high‐diversity silicified assemblage of marine molluscs (Pelsa‐Vazzoler Lagerstätte) from the upper Ladinian of the Agordo Dolomites (northeastern Italy). New data on the Triassic rebound, after the end‐Permian mass extinction, constrain it to an interval of relatively stable climatic conditions. This Lagerstätte, in the Sciliar Formation, yields a structure comparable to the famous lower Carnian San Cassiano Lagerstätte and suggests that the radiation of benthic molluscs may have occurred as early as the late Middle Triassic. We classified more than 4800 Cassian‐type molluscs, measuring abundance distributions of 109 species, including one new family (Rhaetidiidae), three new genera (<jats:italic>Pelsia</jats:italic>, <jats:italic>Gaetania</jats:italic>, <jats:italic>Agordozyga</jats:italic>) and 21 new species: <jats:italic>Grammatodon egortinus</jats:italic>, <jats:italic>Modiolus friesenbichlerae</jats:italic>, <jats:italic>Myoconcha busattae</jats:italic>, <jats:italic>Schizogonium letiziae</jats:italic>, <jats:italic>Predazzella</jats:italic>? <jats:italic>monarii</jats:italic>, <jats:italic>Eucycloscala nitida</jats:italic>, <jats:italic>Tricolnaticopsis elongatus</jats:italic>, <jats:italic>Cortinella stricta</jats:italic>, <jats:italic>Triadoskenea alpicornu</jats:italic>, <jats:italic>Trachynerita tenuicostata</jats:italic>, <jats:italic>Coelostylina civettae</jats:italic>, <jats:italic>Gaetania coronata</jats:italic>, <jats:italic>Agordozyga caprina</jats:italic>, <jats:italic>Euthystylus dincae</jats:italic>, <jats:italic>Zygopleura elongata</jats:italic>, <jats:italic>Diatrypesis agordina</jats:italic>, <jats:italic>Cryptaulax pelsae</jats:italic>, <jats:italic>Pseudoscalites karapunari</jats:italic>, <jats:italic>Promathildia gracile</jats:italic>, <jats:italic>Camponaxis ladinica</jats:italic> and <jats:italic>Striactaeonina ingens</jats:italic>. In this fauna, associated with tropical carbonate platforms, epifaunal filter‐feeding bivalves adopted new antipredatory features and gastropods conquered new ecospace, including parasitism and microcarnivory on sponges and scleractinian corals. Small size was an advantage in an ecosystem of small, isolated patch reefs. This is how, where and when caenogastropod and heterobranch snails (groups that today dominate global marine diversity) began their rise in the marine benthos. The origins of some evolutionary innovations that are key to our understanding of the time and place of the Mesozoic Marine Revolution, are therefore pushed back to the Middle Triassic.","PeriodicalId":48705,"journal":{"name":"Papers in Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Papers in Palaeontology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/spp2.1579","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
We describe a high‐diversity silicified assemblage of marine molluscs (Pelsa‐Vazzoler Lagerstätte) from the upper Ladinian of the Agordo Dolomites (northeastern Italy). New data on the Triassic rebound, after the end‐Permian mass extinction, constrain it to an interval of relatively stable climatic conditions. This Lagerstätte, in the Sciliar Formation, yields a structure comparable to the famous lower Carnian San Cassiano Lagerstätte and suggests that the radiation of benthic molluscs may have occurred as early as the late Middle Triassic. We classified more than 4800 Cassian‐type molluscs, measuring abundance distributions of 109 species, including one new family (Rhaetidiidae), three new genera (Pelsia, Gaetania, Agordozyga) and 21 new species: Grammatodon egortinus, Modiolus friesenbichlerae, Myoconcha busattae, Schizogonium letiziae, Predazzella? monarii, Eucycloscala nitida, Tricolnaticopsis elongatus, Cortinella stricta, Triadoskenea alpicornu, Trachynerita tenuicostata, Coelostylina civettae, Gaetania coronata, Agordozyga caprina, Euthystylus dincae, Zygopleura elongata, Diatrypesis agordina, Cryptaulax pelsae, Pseudoscalites karapunari, Promathildia gracile, Camponaxis ladinica and Striactaeonina ingens. In this fauna, associated with tropical carbonate platforms, epifaunal filter‐feeding bivalves adopted new antipredatory features and gastropods conquered new ecospace, including parasitism and microcarnivory on sponges and scleractinian corals. Small size was an advantage in an ecosystem of small, isolated patch reefs. This is how, where and when caenogastropod and heterobranch snails (groups that today dominate global marine diversity) began their rise in the marine benthos. The origins of some evolutionary innovations that are key to our understanding of the time and place of the Mesozoic Marine Revolution, are therefore pushed back to the Middle Triassic.
期刊介绍:
Papers in Palaeontology is the successor to Special Papers in Palaeontology and a journal of the Palaeontological Association (www.palass.org). The journal is devoted to the publication of papers that document the diversity of past life and its distribution in time and space.
Papers in Palaeontology is devoted to the publication of papers that document the diversity of past life and its distribution in time and space. As a sister publication to Palaeontology its focus is on descriptive research, including the descriptions of new taxa, systematic revisions of higher taxa, detailed biostratigraphical and biogeographical documentation, and descriptions of floras and faunas from specific localities or regions. Most contributions are expected to be less than 30 pp long but longer contributions will be considered if the material merits it, including single topic parts.
The journal publishes a wide variety of papers on palaeontological topics covering:
palaeozoology,
palaeobotany,
systematic studies,
palaeoecology,
micropalaeontology,
palaeobiogeography,
functional morphology,
stratigraphy,
taxonomy,
taphonomy,
palaeoenvironmental reconstruction,
palaeoclimate analysis,
biomineralization studies.