Linda Frey, Michael Coates, Michał Ginter, Vachik Hairapetian, Martin Rücklin, Iwan Jerjen, Christian Klug
{"title":"早期鞘鳃亚目 Phoebodus:系统发育关系、形态学和鲨鱼进化的新时间尺度。","authors":"Linda Frey, Michael Coates, Michał Ginter, Vachik Hairapetian, Martin Rücklin, Iwan Jerjen, Christian Klug","doi":"10.1098/rspb.2019.1336","DOIUrl":null,"url":null,"abstract":"<p><p>Anatomical knowledge of early chondrichthyans and estimates of their phylogeny are improving, but many taxa are still known only from microremains. The nearly cosmopolitan and regionally abundant Devonian genus <i>Phoebodus</i> has long been known solely from isolated teeth and fin spines. Here, we report the first skeletal remains of <i>Phoebodus</i> from the Famennian (Late Devonian) of the Maïder region of Morocco, revealing an anguilliform body, specialized braincase, hyoid arch, elongate jaws and rostrum, complementing its characteristic dentition and ctenacanth fin spines preceding both dorsal fins. Several of these features corroborate a likely close relationship with the Carboniferous species <i>Thrinacodus gracia</i>, and phylogenetic analysis places both taxa securely as members of the elasmobranch stem lineage. Identified as such, phoebodont teeth provide a plausible marker for range extension of the elasmobranchs into the Middle Devonian, thus providing a new minimum date for the origin of the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates, the anguilliform body shape of <i>Phoebodus</i> is unprecedented, and its specialized anatomy is, in several respects, most easily compared with the modern frilled shark <i>Chlamydoselachus</i>. These results add greatly to the morphological, and by implication ecological, disparity of the earliest elasmobranchs.</p>","PeriodicalId":20609,"journal":{"name":"Proceedings of the Royal Society B","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6790773/pdf/","citationCount":"0","resultStr":"{\"title\":\"The early elasmobranch <i>Phoebodus</i>: phylogenetic relationships, ecomorphology and a new time-scale for shark evolution.\",\"authors\":\"Linda Frey, Michael Coates, Michał Ginter, Vachik Hairapetian, Martin Rücklin, Iwan Jerjen, Christian Klug\",\"doi\":\"10.1098/rspb.2019.1336\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Anatomical knowledge of early chondrichthyans and estimates of their phylogeny are improving, but many taxa are still known only from microremains. The nearly cosmopolitan and regionally abundant Devonian genus <i>Phoebodus</i> has long been known solely from isolated teeth and fin spines. Here, we report the first skeletal remains of <i>Phoebodus</i> from the Famennian (Late Devonian) of the Maïder region of Morocco, revealing an anguilliform body, specialized braincase, hyoid arch, elongate jaws and rostrum, complementing its characteristic dentition and ctenacanth fin spines preceding both dorsal fins. Several of these features corroborate a likely close relationship with the Carboniferous species <i>Thrinacodus gracia</i>, and phylogenetic analysis places both taxa securely as members of the elasmobranch stem lineage. Identified as such, phoebodont teeth provide a plausible marker for range extension of the elasmobranchs into the Middle Devonian, thus providing a new minimum date for the origin of the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates, the anguilliform body shape of <i>Phoebodus</i> is unprecedented, and its specialized anatomy is, in several respects, most easily compared with the modern frilled shark <i>Chlamydoselachus</i>. These results add greatly to the morphological, and by implication ecological, disparity of the earliest elasmobranchs.</p>\",\"PeriodicalId\":20609,\"journal\":{\"name\":\"Proceedings of the Royal Society B\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-10-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6790773/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Proceedings of the Royal Society B\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1098/rspb.2019.1336\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2019/10/2 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Royal Society B","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1098/rspb.2019.1336","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2019/10/2 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
The early elasmobranch Phoebodus: phylogenetic relationships, ecomorphology and a new time-scale for shark evolution.
Anatomical knowledge of early chondrichthyans and estimates of their phylogeny are improving, but many taxa are still known only from microremains. The nearly cosmopolitan and regionally abundant Devonian genus Phoebodus has long been known solely from isolated teeth and fin spines. Here, we report the first skeletal remains of Phoebodus from the Famennian (Late Devonian) of the Maïder region of Morocco, revealing an anguilliform body, specialized braincase, hyoid arch, elongate jaws and rostrum, complementing its characteristic dentition and ctenacanth fin spines preceding both dorsal fins. Several of these features corroborate a likely close relationship with the Carboniferous species Thrinacodus gracia, and phylogenetic analysis places both taxa securely as members of the elasmobranch stem lineage. Identified as such, phoebodont teeth provide a plausible marker for range extension of the elasmobranchs into the Middle Devonian, thus providing a new minimum date for the origin of the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates, the anguilliform body shape of Phoebodus is unprecedented, and its specialized anatomy is, in several respects, most easily compared with the modern frilled shark Chlamydoselachus. These results add greatly to the morphological, and by implication ecological, disparity of the earliest elasmobranchs.