REVIEW OF EARLY TRIASSIC THYLACOCEPHALA
Thylacocephala (Euarthropoda: Eucrustacea?) is a group of enigmatic fossil euarthropods, known from at least the Silurian to the Cretaceous. The Triassic is considered to be the period during which thylacocephalans were the most diversified with 17 species reported from 19 localities in nine countri...
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| Format: | Article |
| Language: | English |
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Milano University Press
2021-02-01
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| Series: | Rivista Italiana di Paleontologia e Stratigrafia |
| Subjects: | |
| Online Access: | https://riviste.unimi.it/index.php/RIPS/article/view/15188 |
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| author | THOMAS LAVILLE CHRISTOPHER. P. A. SMITH MARIE-BÉATRICE FOREL ARNAUD BRAYARD SYLVAIN CHARBONNIER |
| author_facet | THOMAS LAVILLE CHRISTOPHER. P. A. SMITH MARIE-BÉATRICE FOREL ARNAUD BRAYARD SYLVAIN CHARBONNIER |
| author_sort | THOMAS LAVILLE |
| collection | DOAJ |
| description | Thylacocephala (Euarthropoda: Eucrustacea?) is a group of enigmatic fossil euarthropods, known from at least the Silurian to the Cretaceous. The Triassic is considered to be the period during which thylacocephalans were the most diversified with 17 species reported from 19 localities in nine countries. However, Thylacocephala were assumed to be rare during the Early Triassic until recent discoveries in Japan, Nevada and Idaho, U.S.A. Our study focuses on thylacocephalans from the Early Triassic, especially from Madagascar and Idaho. The revision of previously known taxa from Madagascar provides new important information. A new kind of ornamentation is reported for Paraostenia ambatolokobensis nov. comb., previously assigned to Ostenocaris ambatolokobensis. In addition, Ankitokazocaris acutirostris and Paraostenia ambatolokobensis are only the third and fourth thylacocephalan taxa for which possible cephalic appendages are described. New occurrences of Thylacocephala in Nevada and Idaho, U.S.A., lead to the description of one new taxon and to the reassignement of Parisicaris triassica to Ankitokazocaris triassica nov. comb. Those occurrences provide a significant contribution to the knowledge of Thylacocephala taxonomic diversity and geographic distribution during the Early Triassic. An important revision of Early Triassic thylacocephalan taxa from Japan and China is also performed, including Ankitokazocaris chaohuensis, Ankitokazocaris parva nov. comb., Ankitokazocaris utatsuensis nov. comb. and Paraostenia sp. Overall, the taxonomic diversity of Triassic thylacocephalans has likely been slightly over-estimated (17 species before, 15 now). However, the Triassic represents the richest period in terms of thylacocephalan-bearing outcrops (19 localities from nine countries). |
| first_indexed | 2024-03-12T20:04:31Z |
| format | Article |
| id | doaj.art-276d80ea335b4dee8545def17910caa5 |
| institution | Directory Open Access Journal |
| issn | 0035-6883 2039-4942 |
| language | English |
| last_indexed | 2024-03-12T20:04:31Z |
| publishDate | 2021-02-01 |
| publisher | Milano University Press |
| record_format | Article |
| series | Rivista Italiana di Paleontologia e Stratigrafia |
| spelling | doaj.art-276d80ea335b4dee8545def17910caa52023-08-02T02:09:52ZengMilano University PressRivista Italiana di Paleontologia e Stratigrafia0035-68832039-49422021-02-01127110.13130/2039-4942/15188REVIEW OF EARLY TRIASSIC THYLACOCEPHALATHOMAS LAVILLECHRISTOPHER. P. A. SMITHMARIE-BÉATRICE FORELARNAUD BRAYARDSYLVAIN CHARBONNIERThylacocephala (Euarthropoda: Eucrustacea?) is a group of enigmatic fossil euarthropods, known from at least the Silurian to the Cretaceous. The Triassic is considered to be the period during which thylacocephalans were the most diversified with 17 species reported from 19 localities in nine countries. However, Thylacocephala were assumed to be rare during the Early Triassic until recent discoveries in Japan, Nevada and Idaho, U.S.A. Our study focuses on thylacocephalans from the Early Triassic, especially from Madagascar and Idaho. The revision of previously known taxa from Madagascar provides new important information. A new kind of ornamentation is reported for Paraostenia ambatolokobensis nov. comb., previously assigned to Ostenocaris ambatolokobensis. In addition, Ankitokazocaris acutirostris and Paraostenia ambatolokobensis are only the third and fourth thylacocephalan taxa for which possible cephalic appendages are described. New occurrences of Thylacocephala in Nevada and Idaho, U.S.A., lead to the description of one new taxon and to the reassignement of Parisicaris triassica to Ankitokazocaris triassica nov. comb. Those occurrences provide a significant contribution to the knowledge of Thylacocephala taxonomic diversity and geographic distribution during the Early Triassic. An important revision of Early Triassic thylacocephalan taxa from Japan and China is also performed, including Ankitokazocaris chaohuensis, Ankitokazocaris parva nov. comb., Ankitokazocaris utatsuensis nov. comb. and Paraostenia sp. Overall, the taxonomic diversity of Triassic thylacocephalans has likely been slightly over-estimated (17 species before, 15 now). However, the Triassic represents the richest period in terms of thylacocephalan-bearing outcrops (19 localities from nine countries).https://riviste.unimi.it/index.php/RIPS/article/view/15188Euarthropoda; biodiversity; Madagascar; Paris biota; Japan; China; cephalic appendages; ornamentation. |
| spellingShingle | THOMAS LAVILLE CHRISTOPHER. P. A. SMITH MARIE-BÉATRICE FOREL ARNAUD BRAYARD SYLVAIN CHARBONNIER REVIEW OF EARLY TRIASSIC THYLACOCEPHALA Rivista Italiana di Paleontologia e Stratigrafia Euarthropoda; biodiversity; Madagascar; Paris biota; Japan; China; cephalic appendages; ornamentation. |
| title | REVIEW OF EARLY TRIASSIC THYLACOCEPHALA |
| title_full | REVIEW OF EARLY TRIASSIC THYLACOCEPHALA |
| title_fullStr | REVIEW OF EARLY TRIASSIC THYLACOCEPHALA |
| title_full_unstemmed | REVIEW OF EARLY TRIASSIC THYLACOCEPHALA |
| title_short | REVIEW OF EARLY TRIASSIC THYLACOCEPHALA |
| title_sort | review of early triassic thylacocephala |
| topic | Euarthropoda; biodiversity; Madagascar; Paris biota; Japan; China; cephalic appendages; ornamentation. |
| url | https://riviste.unimi.it/index.php/RIPS/article/view/15188 |
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