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Along muddy, stone-covered tidal flats on South Korea\u2019s west and south coasts, the odd chiton kept turning up under rocks.<\/p>\n
By comparing those finds, Kyungpook National University (KNU<\/a>) tied the animal to a pattern no named species shared.<\/p>\n Ui Wook Hwang, Ph.D., a biologist at KNU, linked its sharp body needles and central tooth shape to that deeper split.<\/p>\n That problem grows when chitons look so alike on the outside that shape alone can fold separate species into one label.<\/p>\n DNA reveals true identity<\/p>\n Inside each specimen, the team read mitochondrial DNA, the small genome inside cell power centers, to track recent genetic change.<\/p>\n They also checked COI, a short identifying gene widely used to sort closely related animal<\/a> species.<\/p>\n Across five South Korean Acanthochitona species, those sequences and whole genomes separated the newcomer from similar neighbors.<\/p>\n Genetic distance gave the visible differences real weight, instead of leaving them as small quirks on familiar shells.<\/p>\n An ancient body plan<\/p>\n Chitons belong to an old marine group whose basic body plan has stayed recognizable for about 300 million years.<\/p>\n Eight overlapping shell<\/a> plates let them bend against rough surfaces while still clinging tightly in moving water.<\/p>\n That long stability helps explain why a new species can hide in plain sight inside a familiar outline.<\/p>\n Once shells stop giving easy answers, mouthparts and genes start carrying more of the burden.<\/p>\n Named for sharp spines<\/p>\n Researchers named the animal Acanthochitona feroxa, drawing on the Latin ferox, or \u201cfierce,\u201d for its bristling look.<\/p>\n Under magnification, its pointed girdle needles and packed shell granules stopped matching the closest known species.<\/p>\n Its radula, a ribbon of feeding teeth, also carried a central tooth shape that separated it from a close lookalike.<\/p>\n Those details mattered most against A. defilippii, the species whose overall shell form came closest to the newcomer.<\/p>\n Numbers that separated<\/p>\n Hard numbers ended the debate when the team compared COI sequences from 295 animals taken from shores and databases.<\/p>\n Those records collapsed into 97 haplotypes, distinct sequence versions within a species, and then into three clear genetic<\/a> groups.<\/p>\n One lookalike species sat 23 stepwise mutations away from a relative, while the newcomer stood 36 steps from another.<\/p>\n That pattern turned an odd specimen into a repeatable identity, which matters when scientists search other coasts for matches.<\/p>\n A late Cretaceous branch<\/p>\n Beyond identification, the wider family tree placed the South Korean animal inside Acanthochitona and traced the genus back about 83.94 million years.<\/p>\n Using full mitochondrial genomes from 28 chiton<\/a> species across nine families, the researchers dated that split to the Late Cretaceous.<\/p>\n High seas during that period expanded shallow habitat, giving marine animals more room to separate into distinct lines.<\/p>\n Timing alone cannot prove cause, but the match fits an ocean world opening new space for diversification.<\/p>\n Old labels shift<\/p>\n A second surprise reached beyond the new species and into how scientists sort whole branches of chitons.<\/p>\n Earlier phylogenies<\/a>, evolutionary family trees built from genetic evidence, had already hinted that some chiton family labels would not hold up cleanly.<\/p>\n In this study, the family Mopaliidae broke into three lines instead of clustering as a single natural group.<\/p>\n That kind of taxonomic<\/a> repair sounds narrow, but names shape biodiversity records, comparisons, and decisions about what is rare.<\/p>\n Hidden in plain sight<\/p>\n For now, every confirmed record places the species on South Korea\u2019s west and south coasts.<\/p>\n Because it lived under stones in muddy lower shores, ordinary collecting could miss it or misread worn features.<\/p>\n Some specimens showed heavy wear on bristles and shell plates, exactly the kind of damage that blurs species clues.<\/p>\n That mix of hidden habitat and physical wear helps explain how a distinct chiton stayed unnamed this long.<\/p>\n To keep the new species from slipping back into the crowd, KNU published genetic markers and a pictorial guide built from microscopic images.<\/p>\n That guide should help researchers test similar chitons across the western Pacific without relying on shell shape alone.<\/p>\n \u201cThese findings contribute to the understanding of speciation and phylogenetic relationships within the Acanthochitonidae,\u201d Hwang wrote.<\/p>\n Better identifications will make biodiversity surveys, museum records, and future climate tracking far more trustworthy.<\/p>\n What this changes<\/p>\n An animal that looked like one more armored grazer on a tidal rock ended up redrawing part of the chiton family map.<\/p>\n That is the larger lesson of Acanthochitona feroxa: very old body plans still hide new species when evidence sees past the shell.<\/p>\n The study is published in Marine Life Science & Technology<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read?\u00a0Subscribe to our newsletter<\/a>\u00a0for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on\u00a0EarthSnap<\/a>, a free app brought to you by\u00a0Eric Ralls<\/a>\u00a0and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Scientists have identified a previously unknown species of chiton, a small, armored marine mollusk, living along South Korea\u2019s…\n","protected":false},"author":2,"featured_media":386700,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[85,46,141],"class_list":{"0":"post-386699","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-il","9":"tag-israel","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/386699","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=386699"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/386699\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/386700"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=386699"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=386699"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=386699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}