World's oldest footprints found in China

Friday, 08 Jun, 2018

This means that they lived during the Ediacaran Period, which lasted from 635 to 541 million years ago.

But what about Earth - when did animals first leave footprints here?

"They were probably made by millimeter-sized animals with bilateral appendages and can provide important insights into early bilaterian evolution and behaviors".

Animals left the first footprints on Earth up to 551 million years ago, according to ancient tracks found in China.

Life during the Ediacaran was characterized by algae, lichens, giant protozoans, worms, and various bacteria, but there's still a lot that paleontologists don't know about it.

"This is considered the earliest animal fossil footprint record", the researchers wrote in the report.

Bilaterians are one of the most common body types in the world, now and throughout history, but previous fossil evidence for them only goes back as far as the Cambrian.

Until the current discovery, however, no fossil record of animal appendages had been found in that period.

The tracks are actually older than any fossil of a creature with legs, so scientists are puzzled by what created the footprints.

This remarkable discovery is hailed in a study, published yesterday in the journal Science Advances by a research team from Virginia Tech University in the US and the Nanjing Institute of Geology and Palaeontology (NIGP) of the Chinese Academy of Sciences.

While bilaterian animals - including arthropods and annelids - were suspected to have first stretched their innovative legs prior to the Cambrian explosion, in what's called the Ediacaran Period, before now there was no evidence for it in the fossil record.

It was after the Cambrian Explosion that the arthropod and other animal life started flourishing there. They are one of the most diverse animal groups in existence today.

"Previously identified footprints are between 540 and 530 million years old".

The trackways were reportedly leading to burrows, where researchers say it's possible the animal may have dug for food or oxygen.

"Arthropods and annelids, or their ancestors, are possibilities". Maybe they were never preserved, the researchers said.

"Although the exact identity of the trace maker of the Shibantan trackways is hard to determine in the absence of body remains at the end of the trackways, we suggest that the trace maker was probably a bilaterian animal with paired appendages", the authors reported.