The world’s oldest known starfish dating back 480 million years has been excavated in Morocco and is the ‘missing link’ between modern crinoids and their ancestors
- The fossil specimen was excavated from slate in the Anti-Atlas Mountains
- Experts have named the newly identified species ‘Cantabrigiaster fezouataensis’
- It had five feathered arms that were wider than those on modern starfish
- The discovery may help shed light on how sea stars and related animals evolved
A fossil starfish excavated in Morocco that is 480 million years old is a “missing link” between modern crinoids and their ancestors, a study finds.
Cambridge experts said the fossil – discovered from the so-called Fezouata shale of the Anti-Atlas Mountains – is the oldest known starfish.
It dates back to a period in Earth’s history – the so-called Ordovician Biodiversification Event – when life suddenly expanded.
The previous contender for the oldest starfish specimen ever recorded was 50 million years younger, the researchers said.
Given its scientific name ‘Cantabrigiaster fezouataensis’, the ancient species has an intricate design, with feathered arms still visible in the fossil specimens.
The beautifully preserved remains will allow paleontologists to map the body of the new species in detail – and shed light on the evolution of sea stars.
A fossil starfish (pictured) excavated in Morocco that is 480 million years old is a ‘missing link’ between modern crinoids and their ancestors, a study finds.
“Finding this missing link with their ancestors is incredibly exciting,” said evolutionary paleoecologist Aaron Hunter of the University of Cambridge.
“If you went back in time and put your head under the sea in the Ordovician, you wouldn’t recognize any of the marine organisms – except for the starfish, which are one of the first modern animals.”
According to the researchers, C. fezouataensis lacks about 60 percent of the features of a modern starfish’s body plan – instead, it resembles a hybrid between a starfish and a crinoid, or “sea lily.”
Sea lilies are wavy filter feeders that resemble plants in that they are attached to the sea floor via a cylindrical ‘stem’.
“The level of detail in the fossil is astonishing – the structure is so complex it took us a while to unravel its meaning,” said Dr. Hunter.
In their study, Dr. Hunter and his colleague Javier Ortega-Hernandez – formerly also from Cambridge, now based at Harvard University in the US – examined a catalog of hundreds of starfish-like animals in addition to C. fezouataensis.
They indexed all of their body features to assess how the fossil species was related to other members of the ‘echinoderm’ family – a diverse group including sea cucumbers and starfish.
Like most modern species, the fossil has five-fold symmetry – but this ancestral shape had broad arms that were almost pentagonal in outline.
The team plans to expand their work in search of other early echinoderms.
Cantabrigiaster fezouataensis dates back to a period in Earth’s history – the so-called Ordovician Biodiversification Event – when life suddenly expanded
According to the researchers, C. fezouataensis lacks about 60 percent of the features of a modern starfish’s body plan – instead, it resembles a hybrid between a starfish and a “sea lily.”
“One thing we hope to answer in the future is why starfish evolved their five arms,” said Dr. Hunter.
“It appears to be a stable form to assume, but we don’t know why yet.”
“We still have to look for the fossil that gives us that particular connection – but going back to the early ancestors like Cantabrigiaster brings us closer to that answer.”
The full findings of the study are published in the journal Biology Letters.
“Finding this missing link with their ancestors is incredibly exciting,” said evolutionary paleoecologist Aaron Hunter of the University of Cambridge. In the photo, researchers are hunting for starfish fossils in the Fezouata shale (left) of the anti-Atlas Mountains (right)
Cambridge experts said the fossil – discovered from a location (marked) in the so-called Fezouata shale of the Anti-Atlas Mountains – is the oldest known starfish