Two well-preserved species of worms from the Paleozoic era.
Marine worms from 455 million years ago, remains discovered in Morocco.
A research project undertaken by the Complutense University of Madrid (UCM) and the Institute of Geosciences (IGEO, CSIC-UCM) has identified several marine worms from the Paleozoic era (Ordovician period), i.e. 455 million years ago, at the site of Tafilalt Biota in Morocco. They correspond to the new genus and species Anguiscolex africanus and the new species Wronascolex superstes .
Paleoscolecid worms are not uncommon in the Paleozoic; the problem is that 99.99% of the fossil record includes their sclerites (hard plates embedded in the cuticle) isolated, which typically accumulate in some limestone rocks. In other words, this type of worm lived in all the seas of the world, but there is no evidence of its fossils except in a tiny fraction of sites.
The worm fossils from the Moroccan site were articulated and well preserved in lutites ( fine- grained clays , which mainly settle on the bottom of large lakes, off the deltas, in the open sea, in the open ocean) and in an environmental context dominated by turbulent waters, which makes the find, according to the UCM and IGEO paleontologist Juan Carlos Gutiérrez Marco, a “paleontological surprise in a far from favorable geological context”.
These two individuals now add to the discovery, which took place a few years ago in the same site and by the same research group, of the worm Gamascolex vanroyi .
They are worms that lived when Morocco was “polar”
Another of the conclusions highlighted by the study is the “gigantism” of the three known worms in the Tafilalt Biota, which are two to three times larger than the global record for paleoscolecids in Australia, North America and west-central Europe. “This circumstance could be linked to metabolic reasons related to the so-called “polar gigantism”, given that Morocco was very close to the South Pole of the Earth during the Ordovician period,” explains Gutiérrez Marco. This is the third such organism to have been found in the Tafilalt Biota, an extraordinarily well-preserved site that contains a mixture of fossils of groups with hard parts (trilobites, molluscs, echinoderms) and others with a soft or weakly mineralized body (rare arthropods, worms, paropsonemid discs…).
“We are trying to reconstruct the ecosystems and organisms of the past, and the data obtained help in this case to refine the geological correlation of the fossil units of Morocco with other contemporary units located on the marine platform of the former continent of Gondwana”, underlines the researcher of the ‘UCM.
- Polar gigantism and remarkable taxonomic longevity in new palaeoscolecid worms from the Late Ordovician Tafilalt Lagerstätte of Morocco (tandfonline.com)