A chance discovery of a beautifully preserved fossil in the desert landscape of Morocco has solved one of the great mysteries of biology and palaeontology: how starfish evolved their arms.
Starfish are one of the most recognisable animals on our planet. Most people probably associate them with trips to the beach, walking in rock pools or swimming in the sea. They might appear simple creatures, but the way these animals distinctive biology evolved was, until recently, unknown.
Our new study, published in the journal Biology Letters, sheds light on how the starfish developed its distinctive shape.
Starfish, and their close relatives the brittle stars, belong to a group called the echinoderms. These are animals with spiny skins, including sea urchins, sea lilies and sea cucumbers, with bizarre biological traits. They have no head or a brain, and have a unique circulatory system called a water vascular system, which uses seawater instead of blood. They even possess the power to regenerate over 75% of their body mass if it is lost.
Starfish have almost always had the same five-armed body shape. This has not changed for almost 480 million years, throughout the five great mass extinctions they survived.
Other echinoderms use their arms to filter feed or catch food from the water and, unlike starfish, face upwards with their arms spreading outward to feed. But starfish do not, and their distinctive body shape appeared in the fossil record fully formed. So for years scientists have been perplexed by how it evolved and how starfish are related to their close relatives, the brittle stars.
The Fezouata formations are sedimentary rock deposits in Morocco dating back to the early Ordovician period, a critical stage in the evolution of life, which ended around 460 million years ago. Palaeontologists think life rapidly diversified during this time, in an episode call the great Ordovician biodiversification event, when animals we might recognise today first appeared.
The Fezouata formations are a bit like the Pompeii of palaeontology. The conditions on the seabed meant even soft tissue, which would normally be destroyed over time, could be preserved. Because of this, the formations provide a window into what happened at a key moment in the history of life on Earth.
Although starfish might appear very robust animals, they are typically made up of lots of hard parts attached by ligaments and soft tissue which, upon death, quickly degrade. This means we rely on places like the Fezouata formations to provide snapshots of their evolution.
The starfish fossil record is patchy, especially at the critical time when many of these animal groups first appeared. Sorting out how each of the various types of ancient starfish relate to each other is like putting a puzzle together when many of the parts are missing.
Cantabrigiaster is the most primitive starfish-like animal to be discovered in the fossil record. It was discovered in 2003, but it has taken over 17 years to work out its true significance.
What makes Cantabrigiaster unique is that it lacks almost all the characteristics we find in brittle stars and starfish.
Starfish and brittle stars belong to the family Asterozoa. Their ancestors, the Somasteroids were especially fragile - before Cantabrigiaster we only had a handful of specimens. The celebrated Moroccan palaeontologist Mohamed Ben Moula and his local team was instrumental in discovering these amazing fossils near the town of Zagora, in Morocco.
Our breakthrough moment came when I compared the arms of Cantabrigiaster with those of modern sea lilles, filter feeders with long feathery arms that tend to be attached to the sea floor by a stem or stalk.
The striking similarity between these modern filter feeders and the ancient starfish led our team from the University of Cambridge and Harvard University to create a new analysis. We applied a biological model to the features of all the current early Asterozoa fossils in existence, along with a sample of their closest relatives.
Our results demonstrate Cantabrigiaster is the most primitive of all the Asterozoa, and most likely evolved from ancient animals called crinoids that lived 250 million years before dinosaurs. The five arms of starfish are a relic left over from these ancestors. In the case of Cantabrigiaster, and its starfish descendants, it evolved by flipping upside-down so its arms are face down on the sediment to feed.
Although we sampled a relatively small numbers of those ancestors, one of the unexpected outcomes was it provided an idea of how they could be related to each other. Palaeontologists studying echinoderms are often lost in detail as all the different groups are so radically different from each other, so it is hard to tell which evolved first.
Original post:
Starfish: rare fossil helps answer the mystery of how they evolved arms - The Conversation AU
- Vascular Cell and Molecular Biology | Center for Vascular Biology | Weill Cornell ... - April 13th, 2018 [April 13th, 2018]
- APVBO-Asia Pacific Vascular Biology Organization Conference - April 18th, 2018 [April 18th, 2018]
- Vascular Biology Conferences | Vascular Surgery ... - May 5th, 2018 [May 5th, 2018]
- Vascular Discovery: From Genes to Medicine - May 7th, 2018 [May 7th, 2018]
- 2019 Vascular Cell Biology Conference GRC - May 26th, 2018 [May 26th, 2018]
- Biology 211: Taxonomy of Flowering Plants - June 7th, 2018 [June 7th, 2018]
- esm-evbo2019.org - Menu - July 27th, 2018 [July 27th, 2018]
- Vascular Biology | Pulmonary, Allergy, Sleep & Critical ... - November 16th, 2018 [November 16th, 2018]
- Lower vascular plant | biology | Britannica.com - November 18th, 2018 [November 18th, 2018]
- Vascular Biology - NAVBO - November 20th, 2018 [November 20th, 2018]
- 2019 Cerebral Vascular Biology Conference - cvent.com - November 21st, 2018 [November 21st, 2018]
- PPARs and Their Emerging Role in Vascular Biology ... - November 26th, 2018 [November 26th, 2018]
- Vascular Biology Chicago Medicine - November 30th, 2018 [November 30th, 2018]
- Vascular Biology | Society for Vascular Surgery - November 30th, 2018 [November 30th, 2018]
- Vascular Biology 2018 - NAVBO - December 19th, 2018 [December 19th, 2018]
- Vascular Biology 2019 - NAVBO - December 20th, 2018 [December 20th, 2018]
- Vascular Biology - January 22nd, 2019 [January 22nd, 2019]
- pvb2019.org Plant Vascular Biology Conference 2019 - January 31st, 2019 [January 31st, 2019]
- Plant Physiology | Basic Biology - March 12th, 2019 [March 12th, 2019]
- Awards - esm-evbo2019.org - April 23rd, 2019 [April 23rd, 2019]
- Medication and Exercise to Prevent Muscle Loss - Next Avenue - September 24th, 2019 [September 24th, 2019]
- A Snail as Fast as a Bullet, and Other Darwin-Defying Marvels - Discovery Institute - September 24th, 2019 [September 24th, 2019]
- Nature up close: Life in the Humboldt Penguin National Reserve - CBS News - September 24th, 2019 [September 24th, 2019]
- Oklahoma new hires and promotions announced - Oklahoman.com - September 24th, 2019 [September 24th, 2019]
- Quinn Capers IV, MD - TCTMD - September 24th, 2019 [September 24th, 2019]
- Cardiovascular Repair And Reconstruction Devices Market Global Industry Insights by Top Vendors, Growth, Revenue and Forecast Outlook 2019-2025 -... - September 26th, 2019 [September 26th, 2019]
- Four health projects at Boston Childrens Hospital that could help adults - The Boston Globe - September 30th, 2019 [September 30th, 2019]
- Research Officer/ Postdoctoral Researcher - The Conversation AU - October 16th, 2019 [October 16th, 2019]
- UNSW skin cancer researcher Levon Khachigian hit with string of retractions - ABC News - October 16th, 2019 [October 16th, 2019]
- Michal Wszola: We Expect to Transplant the Bioprinted Bionic Pancreas in Three to Five Years - 3DPrint.com - October 24th, 2019 [October 24th, 2019]
- 'The Blob': This mysterious 'smart' slime can solve puzzles and make decisions - CNBC - October 24th, 2019 [October 24th, 2019]
- University of Maryland and DOD collaborate to study Tick-borne Infections using 3-D models of human blood vessels - Outbreak News Today - November 19th, 2019 [November 19th, 2019]
- Submerged Vegetation Mirrors Coast's Health - Coastal Review Online - November 19th, 2019 [November 19th, 2019]
- Another health warning for e-cigarette users that has nothing to do with lung disease - MarketWatch - November 19th, 2019 [November 19th, 2019]
- E-Cigarettes Take a Dangerous Toll on Heart Health - DocWire News - November 19th, 2019 [November 19th, 2019]
- Vascular biology Department of Surgery College of ... - November 19th, 2019 [November 19th, 2019]
- US Nobel laureates tell us what they think about cancer research, moonshots, the dark side, funding, meritocracy, herd mentality, Trump, and joy - The... - November 21st, 2019 [November 21st, 2019]
- Growing Organs in the Lab: One Step Closer to Reality - BioSpace - November 21st, 2019 [November 21st, 2019]
- Inotrem Announces Enrollment of First Patient in its Phase IIb ASTONISH Trial for Nangibotide in the Treatment of Septic Shock - Business Wire - November 21st, 2019 [November 21st, 2019]
- Another Study Suggests E-cigarettes Hurt Heart Health More Than Regular Cigarettes - Science Times - November 21st, 2019 [November 21st, 2019]
- Cleveland Clinic awarded $12 million by NIH to study the link between gut microbes and heart disease - Crain's Cleveland Business - November 21st, 2019 [November 21st, 2019]
- JanOne Acquires Worldwide, Exclusive License for Promising Treatment of Peripheral Arterial Disease (PAD) - Yahoo Finance - November 27th, 2019 [November 27th, 2019]
- Germ-free lungs of newborn mice are partially protected against hyperoxia - The Mix - November 27th, 2019 [November 27th, 2019]
- Bethesda Health Physician Group Welcomes Fellowship-Trained Endocrine Surgeon Jessica L. Buicko, MD, to Its Team - The Boca Raton Tribune - November 27th, 2019 [November 27th, 2019]
- 9 Harvard researchers named AAAS Fellows Harvard - Harvard Gazette - November 27th, 2019 [November 27th, 2019]
- Top Technical Advances of 2019 - The Scientist - December 29th, 2019 [December 29th, 2019]
- Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy Nanotyrannus and supports ontogenetic niche partitioning in juvenile Tyrannosaurus -... - January 2nd, 2020 [January 2nd, 2020]
- UCC currently taking applicants for 21 jobs with some incredible pay - Cork Beo - January 2nd, 2020 [January 2nd, 2020]
- Vascular Biology | Surgery Research | Michigan Medicine ... - January 2nd, 2020 [January 2nd, 2020]
- Sandy Bottom wetlands to receive protection for 'national ecological significance' - Citizen Times - January 14th, 2020 [January 14th, 2020]
- Why biotech is a boon for patients and investors - Spear's WMS - January 14th, 2020 [January 14th, 2020]
- Exonate Announces Collaboration With Janssen to Develop a New Eye Drop for the Treatment of Retinal Vascular Diseases Including Wet Age-related... - January 14th, 2020 [January 14th, 2020]
- G-protein Coupled Receptor Market Competitive Research And Precise Outlook 2019 To 2025 Dagoretti News - Dagoretti News - January 18th, 2020 [January 18th, 2020]
- Scientists revealed the oldest known scorpion on Earth - Tech Explorist - January 18th, 2020 [January 18th, 2020]
- How biology creates networks that are cheap, robust, and efficient - Penn: Office of University Communications - January 18th, 2020 [January 18th, 2020]
- Genome editing heralds new era of disease research, therapy - The Augusta Chronicle - January 18th, 2020 [January 18th, 2020]
- Research Fellow in Vascular Stem Cell Biology job with QUEENS UNIVERSITY BELFAST | 195527 - Times Higher Education (THE) - February 10th, 2020 [February 10th, 2020]
- More than skin deep: the latest innovation in 3D printing - Med-Tech Innovation - February 10th, 2020 [February 10th, 2020]
- Examining the link between menopause and heart disease risk - Medical News Bulletin - February 10th, 2020 [February 10th, 2020]
- Women Face an Increased Risk of Heart Disease With AgeRunning Can Help - runnersworld.com - February 12th, 2020 [February 12th, 2020]
- G-protein Coupled Receptor Market Competitive Research And Precise Outlook 2019 To 2025 - Galus Australis - February 15th, 2020 [February 15th, 2020]
- Valentine's Day Matters of the Heart, Biopharma-Style - BioSpace - February 15th, 2020 [February 15th, 2020]
- The Addicted Gardener: Environmental tidbits from around the world - Wicked Local Sharon - February 22nd, 2020 [February 22nd, 2020]
- UI at 150 & Beyond: 'The Quad was the best no matter what the weather' - Champaign/Urbana News-Gazette - February 22nd, 2020 [February 22nd, 2020]
- The Addicted Gardener: Environmental tidbits from around the world - Wicked Local Dedham - February 23rd, 2020 [February 23rd, 2020]
- THE ADDICTED GARDENER: Environmental tidbits from around the world - Wicked Local Wareham - March 22nd, 2020 [March 22nd, 2020]
- 'Little Foot' skull reveals how this more than 3 million year old human ancestor lived - HeritageDaily - March 22nd, 2020 [March 22nd, 2020]
- It's Not Only About Neurons - The Good Men Project - March 22nd, 2020 [March 22nd, 2020]
- Who is Sir Patrick Vallance and what is his role in government during coronavirus outbreak? - The Scottish Sun - March 22nd, 2020 [March 22nd, 2020]
- University of Washington Pathology Professor Dies of COVID-19 - The Scientist - March 22nd, 2020 [March 22nd, 2020]
- THE ADDICTED GARDENER: Environmental tidbits from around the world - Wicked Local Rochester - March 23rd, 2020 [March 23rd, 2020]
- Ancient human ancestor 'Little Foot' probably lived in trees, new research finds - WBAP News/Talk - March 23rd, 2020 [March 23rd, 2020]
- Study shows similarity in anti-VEGF injection intervals for wet AMD - Ophthalmology Times - March 25th, 2020 [March 25th, 2020]
- aTyr Pharma and its Hong Kong Subsidiary, Pangu BioPharma, Announce Government Grant to Fund Bispecific Antibody Development Platform - BioSpace - March 25th, 2020 [March 25th, 2020]
- Health researchers find solution to life-threatening side effect - Mirage News - March 25th, 2020 [March 25th, 2020]
- European Vascular Biology Organisation | Advancing human ... - March 25th, 2020 [March 25th, 2020]
- Vascular Biology Program | Boston Children's Hospital - March 25th, 2020 [March 25th, 2020]
- Vascular Biology Research Program | Johns Hopkins ... - March 25th, 2020 [March 25th, 2020]
- Anatomy of a heatwave: how Antarctica recorded a 20.75C day last month - The Conversation AU - April 1st, 2020 [April 1st, 2020]
- Who is Sir Patrick Vallance and is he speaking at todays government coronavirus press briefing? - The Sun - April 1st, 2020 [April 1st, 2020]