Roughly 500 million years ago, a strange event in the evolution of life on Earth seems to have taken place.<\/p>\n
The known fossil record from this time, which falls within the Cambrian period, contains a missing chapter. Palaeontologists refer to it as the \u201cFurongian gap\u201d. And it\u2019s striking because there is an explosion of biodiversity within the fossil record both immediately before and after it.<\/p>\n
This decline has been considered evidence for a real biological crisis \u2013 one driven by environmental instability, changing ocean chemistry, cooling climates, a lack of oxygen in ancient seas, or a combination of these factors.<\/p>\n
Our new study, published in the journal BMC Biology, provides new evidence for an alternative idea. The Furongian may not represent a true collapse in biodiversity, but rather a gap in where scientists have looked and what kinds of rocks have been studied.<\/p>\n
It\u2019s a reminder of how incomplete our understanding of Earth\u2019s history remains.<\/p>\n
A rare group of fossils<\/p>\n
We describe a new 500-million-year-old arthropod from Qu\u00e9bec, Canada. Arthropods are animals with exoskeletons \u2013 that is, skeletons on the exterior of their bodies.<\/p>\n
The fossil belongs to a rare group of early arthropods related to the lineage leading to spiders and scorpions. Importantly, it comes from a geological setting that scientists have not previously recognised as being notable for preserving fossils at this time in Earth\u2019s history.<\/p>\n
The fossil itself is named Magnicornaspis garwoodi. The animal belongs to the corcoraniids \u2013 an enigmatic group of early arthropods that have broad head shields, segmented bodies, and defensive spines.<\/p>\n
Corcoraniids remain exceptionally rare globally. Only a handful of species are known from the Cambrian and Ordovician periods.<\/p>\n
Our specimen is unique for its two large forward-projecting spines extending from the head. These exaggerated spines distinguish the species from previously known relatives. They suggest defensive adaptations within the group evolved earlier than previously recognised.<\/p>\n
Sitting in a museum drawer for decades<\/p>\n
The specimen was originally collected in 1962 during geological mapping near Sainte-Anne-de-la-Pocati\u00e8re in Qu\u00e9bec. It came from mudstones within the Rivi\u00e8re-du-Loup Formation. This formation was deposited in relatively deep marine slope environments during the late Cambrian.<\/p>\n
This represents quieter offshore conditions where fine mud settled through the water column. These rocks have received relatively little palaeontological attention, making them ideal for reassessment.<\/p>\n","protected":false},"excerpt":{"rendered":"Roughly 500 million years ago, a strange event in the evolution of life on Earth seems to have…\n","protected":false},"author":2,"featured_media":705043,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[284301,64,63,284540,343033,343032,128],"class_list":["post-705042","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-arthropod","tag-au","tag-australia","tag-cambrian-period","tag-fossil-record","tag-palaeontologists","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/705042","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=705042"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/705042\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/705043"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=705042"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=705042"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=705042"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}