New phylum in animal kingdom found


This video is called Xenoturbella in action.

From the University of Florida:

Genetic analysis of an obscure, worm-like creature retrieved from the depths of the North Atlantic has led to the discovery of a new phylum, a rare event in an era when most organisms have already been grouped into major evolutionary categories.

The analysis also appears to shed light on the ancestor of chordates, the backboned animals that include human beings and two small invertebrate groups closely related to one another: lancelets and tunicates.

“It’s a tremendous surprise that this mysterious creature from the ocean will help us understand our distant past,” said Leonid Moroz, a professor of neuroscience and zoology at UF’s Whitney Laboratory for Marine Bioscience near St. Augustine and one of the researchers who participated in the discovery.

Moroz and 13 other scientists report their findings today in the journal Nature.

Scientists have long been puzzled by the half-inch-long creature known by its scientific name of Xenoturbella and first retrieved from the Baltic Sea more than 50 years ago.

Early genetic research identified it as a type of mollusk. But then scientists discovered the mollusk-like DNA actually resulted not from the creature itself, but from its close association to clams and likely habit of eating mollusk eggs, Moroz said.

The Xenoturbella does not seem to have a brain, gut or gonads, making it unique among living animals.

More precise genomic sequencing at the Whitney Lab – where Moroz and his collaborators identified about 1,300 genes including mitochondrial genes – helped to reveal a surprise: Xenoturbella belongs to its own phylum, a broad class of organisms lying just below kingdom in taxonomic classification.

It is one of only about 32 such phyla in the animal kingdom. “During the last 50 to 60 years, only a few new phyla have been established,” Moroz said.

Perhaps more significant, the analysis of Xenoturbella seems to confirm that human beings and other chordates share a common ancestor, a first in science.

Its extreme characteristics suggest that this common ancestor – one the creature shares with its sister phyla, echinoderms and hemichordates, as well as chordates — did not have a brain or central nervous system.

Researchers are arguing about whether or not the Xenoturbella bocki worm is the progenitor of mankind. But new studies indicate that this is actually the case. Swedish researchers from the University of Gothenburg and the Gothenburg Natural History Museum are involved in the international study. The results have been published in Nature Communications: here.

Sea urchin genome: here.

Invasive tunicates in North America: here.

Salps: here.

1 thought on “New phylum in animal kingdom found

  1. Pingback: New deep sea Xenoturbella worm species discovered | Dear Kitty. Some blog

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