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Home / Science / Paleontologists discover evolutionary links between Ediacaran and early Cambrian multicellular animals

Paleontologists discover evolutionary links between Ediacaran and early Cambrian multicellular animals



Paleontologists describe the first soft tissue preservation in three-dimensional tissue And cal po hermanastes, A skeletal metazoan (multicellular animal) that lived approximately 547 million years ago (Ediacaran period), now Namibia, and established a strong relationship between Ediacaran and Early Cambrian metazoans Evolutionary connection.

Namacalathus (personal number). Centimeter scale. Image source: Shore et al., doi: 10.1126/sciadv.abf2933.

Nacamarasius (My Number). Centimeter scale. Image source: Shore Wait. , Doi: 1

0.1126/sciadv.abf2933.

Until recently, due to the lack of well-preserved fossil evidence, little was known about the origin of the animals that evolved during the Cambrian explosion.

The mysterious origin of the animals evolved at that time puzzled the 19th century naturalist Charles Darwin. It is often called Darwin’s dilemma.

Prior to the new research, it had proved difficult to trace the connection with early animals, because their soft tissues (providing important clues about the ancestry of animals) almost always ruptured over time.

During a field trip in Namibia, Professor Rachel Wood of the University of Edinburgh and his colleagues unearthed well-preserved fossil remains. And cal po hermanastes.

Using X-ray imaging technology, they discovered that the soft tissues of some animals are completely preserved inside the fossils called pyrite.

So far, paleontologists have only found And cal po hermanastes.

Reconstruction of live macaques: 1-stem; 2-parenting cup; 3-daughter cup; 4-hollow ciliated tentacles; 5-spine; 6-lateral cavity; 7-central opening; 8-endoskeletal layer with columnar micro-lamella bending 9-The inner (middle) bones are later, organically rich; 10-The outer layer of the outer bones, leaf-like bones are curved. Image source: J.  Sibbick.

Rebuild life Nacamarasius: 1-Stem; 2-Childcare cup; 3-Sub cup; 4-Hollow ciliated tentacles; 5-Spines; 6-Lateral cavity; 7-Central opening; 8-Endoskeletal layer, with columnar micro-lamella bending; 9-Internal (Middle) The bones are later, organically rich; 10-The outer layer of the outer skeleton, the leaf-like bones are curved. Image source: J. Sibbick.

Professor Wood and his co-authors then examined the soft tissues of Ediacaran animals and compared them with those of animals that evolved later.

They found And cal po hermanastes It is the early ancestor of the species that appeared during the Cambrian outbreak. Among them are prehistoric worms and mollusks.

Professor Wood said: “These are special fossils that allow us to understand the biological affinity of some of the oldest animals.”

“They helped us trace the origin of the Cambrian explosion and the origin of modern animal groups.”

“Such preservation opens up many new research avenues for life history, which was impossible before.”

The research was published in the journal Scientific progress.

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AJ Shore Wait. 2021. Ediacaran metazoan reveals the affinity of secondary nourishment animals and deepens the origin of the Cambrian outbreak. Scientific progress 7(1): eabf2933; doi: 10.1126 / sciadv.abf2933


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