• HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
Sunday, August 3, 2025
BIOENGINEER.ORG
No Result
View All Result
  • Login
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
No Result
View All Result
Bioengineer.org
No Result
View All Result
Home NEWS Science News Biology

Half a billion-year-old spiny slug reveals the origins of mollusks

by
August 1, 2024
in Biology
Reading Time: 6 mins read
0
Share on FacebookShare on TwitterShare on LinkedinShare on RedditShare on Telegram

 

Sclerite.png

Credit: G Zhang/L Parry.

UNDER EMBARGO UNTIL 19:00 BST / 14:00 ET THURSDAY 1 AUGUST 2024

 

Images available via link in the notes section

 

  • Exceptional fossils with preserved soft parts reveal that the earliest molluscs were flat, armoured slugs without shells.
  • The new species, Shishania aculeata was covered with hollow, organic, cone-shaped spines.
  • The fossils preserve exceptionally rare detailed features which reveal that these spines were produced using a sophisticated secretion system that is shared with annelids (earthworms and relatives).

A team of researchers including scientists from the University of Oxford have made an astonishing discovery of a new species of mollusc that lived 500 million years ago. The new fossil, called Shishania aculeata*, reveals that the most primitive molluscs were flat, shell-less slugs covered in a protective spiny armour. The findings have been published today in the journal Science.

The new species was found in exceptionally well-preserved fossils from eastern Yunnan Province in southern China dating from a geological Period called the early Cambrian, approximately 514 million years ago. The specimens of Shishania are all only a few centimetres long and are covered in small spikey cones (sclerites) made of chitin, a material also found in the shells of modern crabs, insects, and some mushrooms.

Specimens that were preserved upside down show that the bottom of the animal was naked, with a muscular foot like that of a slug that Shishania would have used to creep around the seafloor over half a billion years ago. Unlike most molluscs, Shishania did not have a shell that covered its body, suggesting that it represents a very early stage in molluscan evolution.

Present-day molluscs have a dizzying array of forms, and include snails and clams and even highly intelligent groups such as squids and octopuses. This diversity of molluscs evolved very rapidly a long time ago, during an event known as the Cambrian Explosion, when all the major groups of animals were rapidly diversifying. This rapid period of evolutionary change means that few fossils have been left behind that chronicle the early evolution of molluscs.

Corresponding author Associate Professor Luke Parry, Department of Earth Sciences, University of Oxford, said: ‘Trying to unravel what the common ancestor of animals as different as a squid and oyster looked like is a major challenge for evolutionary biologists and palaeontologists – one that can’t be solved by studying only species alive today. Shishania gives us a unique view into a time in mollusc evolution for which we have very few fossils, informing us that the very earliest mollusc ancestors were armoured spiny slugs, prior to the evolution of the shells that we see in modern snails and clams.’

Because the body of Shishania was very soft and made of tissues that don’t typically preserve in the fossil record, the specimens were challenging to study, as many of the specimens were poorly preserved.

First author Guangxu Zhang, a recent PhD graduate from Yunnan University in China who discovered the specimens said: ‘At first I thought that the fossils, which were only about the size of my thumb, were not noticeable, but I saw under a magnifying glass that they seemed strange, spiny, and completely different from any other fossils that I had seen. I called it “the plastic bag” initially because it looks like a rotting little plastic bag. When I found more of these fossils and analysed them in the lab I realised that it was a mollusc.’

Associate Professor Parry added: ‘We found microscopic details inside the conical spines covering the body of Shishania that show how they were secreted in life. This sort of information is incredibly rare, even in exceptionally preserved fossils.’

The spines of Shishania show an internal system of canals that are less than a hundredth of a millimetre in diameter. These features show that the cones were secreted at their base by microvilli, tiny protrusions of cells that increase surface area, such as in our intestines where they aid food absorption.

This method of secreting hard parts is akin to a natural 3D printer, allowing many invertebrate animals to secrete hard parts with huge variation of shape and function from providing defence to facilitating locomotion.

Hard spines and bristles are known in some present-day molluscs (such as chitons), but they are made of the mineral calcium carbonate rather than organic chitin as in Shishania. Similar organic chitinous bristles are found in more obscure groups of animals such as brachiopods and bryozoans, which together with molluscs and annelids (earthworms and their relatives) form the group Lophotrochozoa.

Professor Parry added: ‘Shishania tells us that the spines and spicules we see in chitons and aplacophoran molluscs today actually evolved from organic sclerites like those of annelids. These animals are very different from one another today and so fossils like Shishania tell us what they looked like deep in the past, soon after they had diverged from common ancestors.’

Co-author Jakob Vinther at the University of Bristol said: ‘Molluscs today are extraordinarily disparate and they diversified very quickly during the Cambrian Explosion, meaning that we struggle to piece together their early evolutionary history. We know that the common ancestor of all molluscs alive today would have had a single shell, and so Shishania tells us about a very early time in mollusc evolution before the evolution of a shell.’

Co-corresponding author Xiaoya Ma (Yunnan University and University of Exeter) said: ‘This new discovery highlights the treasure trove of early animal fossils that are preserved in the Cambrian rocks of Yunnan Province. Soft bodied molluscs have a very limited fossil record, and so these very rare discoveries tell us a great deal about these diverse animals.’

*Etymology of Shishania aculeata: Shishan refers to Shishan Zhang, for his outstanding contributions to the study of early Cambrian strata and fossils in eastern Yunnan; aculeata (Latin), having spines, prickly.

Notes:

For media enquiries and interview requests, contact Associate Professor Luke Parry [email protected]

Images relating to the study which can be used in articles can be found at https://drive.google.com/drive/folders/1eLiDU7bDWpVyxNJK9IzevPGL2ORud86n?usp=drive_link  These images are for editorial purposes only and MUST be credited (see captions document in file). They MUST NOT be sold on to third parties.

The study ‘A Cambrian spiny stem mollusk and the deep homology of lophotrochozoan scleritomes’ will be published in the journal Science at 19:00 BST / 14:00 ET Thursday 1 August 2024 at www.science.org/doi/10.1126/science.ado0059   (link will go live when embargo lifts). To view a copy of the study before this, under embargo, contact the Science editorial team at [email protected] or see the Science press package at https://www.eurekalert.org/press/scipak/

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the eighth year running, and ​number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.



Journal

Science

DOI

10.1126/science.ado0059

Article Title

A Cambrian spiny stem mollusk and the deep homology of lophotrochozoan scleritomes

Article Publication Date

2-Aug-2024

Share12Tweet8Share2ShareShareShare2

Related Posts

blank

CK2–PRC2 Signal Drives Plant Cold Memory Epigenetics

August 2, 2025
blank

AI-Driven Protein Design Advances T-Cell Immunotherapy Breakthroughs

August 1, 2025

Melanthiaceae Genomes Reveal Giant Genome Evolution Secrets

August 1, 2025

“Shore Wars: New Study Tackles Oyster-Mangrove Conflicts to Boost Coastal Restoration”

August 1, 2025

POPULAR NEWS

  • Blind to the Burn

    Overlooked Dangers: Debunking Common Myths About Skin Cancer Risk in the U.S.

    60 shares
    Share 24 Tweet 15
  • Neuropsychiatric Risks Linked to COVID-19 Revealed

    47 shares
    Share 19 Tweet 12
  • Dr. Miriam Merad Honored with French Knighthood for Groundbreaking Contributions to Science and Medicine

    46 shares
    Share 18 Tweet 12
  • Study Reveals Beta-HPV Directly Causes Skin Cancer in Immunocompromised Individuals

    38 shares
    Share 15 Tweet 10

About

We bring you the latest biotechnology news from best research centers and universities around the world. Check our website.

Follow us

Recent News

Zinc Finger Protein 683 Predicts Kidney Cancer Immunity

LONP1 Controls Mitochondrial Folding, Impacts Diabetes

Boosting Healthcare Wearables with Self-Supervised Learning

  • Contact Us

Bioengineer.org © Copyright 2023 All Rights Reserved.

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In
No Result
View All Result
  • Homepages
    • Home Page 1
    • Home Page 2
  • News
  • National
  • Business
  • Health
  • Lifestyle
  • Science

Bioengineer.org © Copyright 2023 All Rights Reserved.