Scorpion mothers carry still-soft-shelled babes on their backs, reminding us that even arachnids can be adorable \u2013 never mind that a peckish mama might decide to devour a scorpling<\/a> or two.<\/p>\n But exploring the evolutionary roots of these diverse maternal methods is tough, because reproductive tissues decay quickly after an animal’s death.<\/p>\n Now, an incredible discovery published in Scientific Reports<\/a>\u00a0offers some rare insight: an international research team has described a 125-million-year-old ‘pregnant’ shellfish with preserved soft tissues, including its itty-bitty babies.<\/p>\n Scientists have searched for a specimen like this for decades.<\/p>\n “This is the earliest known fossil evidence that these shellfish cared for and protected their developing young. Until now, this reproductive strategy was known only from living species,” says<\/a> Martin Munt, a curator at the Dinosaur Isle Museum in the UK and a visiting researcher at the University of Portsmouth.<\/p>\n The ancient shellfish, a creature not generally imagined as motherly, is a bivalve. It belongs to a huge group of double-shelled mollusks, comprising more than 40,000 fossil and 50,000 extant species, including a who’s who of seafood-dish toppings, such as clams, oysters, scallops, and mussels<\/a>.<\/p>\n The fossilized shellfish specimens were found on the Isle of Wight, an island off the southern coast of England and a site famous for its plentiful Cretaceous fossil finds, including what may have been one of Europe’s largest terrestrial terrors<\/a>.<\/p>\n “Not only does this discovery provide a rare glimpse into how ancient freshwater shellfish reproduced,” Munt says<\/a>, “but it also helps explain how these animals successfully adapted to life in rivers and lakes millions of years ago.”<\/p>\n The creatures studied herein, Margaritifera valdensis, are distantly related to today’s freshwater pearl mussels, which encompass up to 1,000 living species.<\/p>\n They also have one of the most unique reproductive strategies among all invertebrates, worthy of a xenomorph<\/a>.<\/p>\n First, a basic birds-and-bees scenario occurs: Males release sperm into the water, which the females siphon and use to fertilize eggs inside a brood chamber that sits within a specialized portion of their gills.<\/p>\n In addition to shelter, the mother mollusks provide their growing young with calcium, a mineral that may have helped preserve these specimens.<\/p>\n The young then develop into larvae which, like parasites, must infect fish to mature. The larvae attach to gills and fins and grow under a fish’s skin<\/a>, eventually dropping away to form new mussel beds.<\/p>\n (Comparatively, the mammalian dinner-and-movie reproductive technique seems much more straightforward.)<\/p>\n “These new fossils demonstrate that this complex reproductive strategy had already evolved by the Early Cretaceous,” says<\/a> Aleksandra Skawina, an expert in fossil bivalves at the University of Warsaw and study co-author.<\/p>\n This research also elucidates the origin of a dark, mysterious ‘molluskite’ material first described<\/a> nearly 200 years ago.<\/p>\n “We found that this material is actually made up of fossilised soft tissues and reproductive structures that have been exceptionally preserved by minerals,” explains<\/a> study co-author Rafael P. Lozano, a geochemist at the Geological and Mining Institute of Spain.<\/p>\n Unfortunately, these amazing animals are currently among the most threatened creatures<\/a>. Pollution, construction projects, exploration, climate change<\/a>, and other factors are destroying freshwater systems<\/a>.<\/p>\n While we can applaud their sexual adaptability, mollusks are often overlooked as drab little shells \u2013 even though they represent the second-largest phylum of invertebrates<\/a> after arthropods.<\/p>\n Related:\u00a0Condors Had ‘Virgin Births’ Despite Having Access to Fertile Mates, a First For Birds<\/a><\/p>\n And they are a key component of modern freshwater ecosystems, so we would do well to watch them closely: they might already be ringing alarm bells<\/a> of Earth’s sixth mass extinction.<\/p>\n This research was published in Scientific Reports<\/a>.<\/p>\n This article was fact-checked by Rachel Garner<\/a> and edited by Clare Watson<\/a>. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Nature has imbued its mothers with many surprisingly strange ways to reproduce and care for their babies. Some…\n","protected":false},"author":2,"featured_media":534089,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,2209,82],"class_list":["post-534088","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-msft-content","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/534088","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=534088"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/534088\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/534089"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=534088"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=534088"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=534088"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/Untitled-design-21.jpg\")
One of the incredibly well-preserved Cretaceous freshwater shellfish. (University of Portsmouth)<\/a><\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/Foto-4.jpg.webp\")
A cross-section of a ‘pregnant’ bivalve, preserved with embryos and larvae. (University of Portsmouth)<\/a><\/p>\n![\"An](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/41598_2026_56499_Fig4_HTML.png\")
The 125-million-year-old ‘babies’ are shown in images b and d, at different levels of early development, including oogonia and incipient embryos, respectively. Images a and c show gonads and ovaries in extant (living) freshwater bivalves, respectively. (Delvene et al., Scientific Reports, 2026)<\/a><\/p>\n![\"Subscribe](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/06\/FOMO-1200x628-_Dont-miss-the-next-breakthrough_-cosmic-colourful-642x336.jpg\")
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