New fossil reveals origin of arthropod breathing system

Date:
February 7, 2022
Source:
University of Manchester
Summary:
Scientists have discovered a new fossil that reveals the origin
of gills in arthropods.



FULL STORY ========================================================================== University of Manchester research fellow David Legg, in collaboration
with a team of international scientists from China, Switzerland, and
Sweden, has today announced a new fossil that reveals the origin of
gills in arthropods.


========================================================================== Arthropods, the group of animals that includes creepy crawlies like
spiders and woodlice, are the largest phylum in the animal kingdom
and are found everywhere from the deepest ocean trench to the top of
Mount Everest.

Research published today shows the newest addition to the group
is a 520- million-year-old (about 10 times as old as the dinosaurs)
organism called Erratus sperare. Erratus sperare was discovered in the Chengjiang Fossil Site, a UNESCO World Heritage Site located in Yunnan,
China. The Chengjiang Fossil Site preserves an ancient underwater
ecosystem which included the relatives of some well-known arthropod
fossils like trilobites and anomalocarids.

Modern water dwelling arthropods have biramous limbs, legs that have two
parts -- one for breathing and one for walking -- but how such specialised limbs evolved was a mystery. Some of the earliest fossil arthropods,
like Anomalocaris,had swimming flaps that may have doubled as gills,
but until now researchers didn't know how arthropods made the jump from
these specialised flaps to the biramous limbs of modern arthropods.

Erratus sperare provides the missing link between arthropods that used
such specialised flaps and arthropods with biramous limbs. It has both
legs and flaps.

Dr David Legg, one of the authors of this study, said: "Fish aren't the
only organisms that have gills! Arthropods have gills too... they just
have them on their legs. When it came to arthropods, however, we just
weren't sure where these gills came from.

"Thanks to this new fossil, Erratus sperare, we now have a much clearer
idea.

These gills also probably went on to evolve into
the wings of insects and the lungs of terrestrial
arthropods like spiders so were a very important innovation." ========================================================================== Story Source: Materials provided by University_of_Manchester. Note:
Content may be edited for style and length.


========================================================================== Related Multimedia:
* Artist's_impression_of_arthropod_that_lived_520-million-years_ago ========================================================================== Journal Reference:
1. Dongjing Fu, David A. Legg, Allison C. Daley, Graham E. Budd, Yu Wu,
Xingliang Zhang. The evolution of biramous appendages revealed by
a carapace-bearing Cambrian arthropod. Philosophical Transactions
of the Royal Society B: Biological Sciences, 2022; 377 (1847) DOI:
10.1098/ rstb.2021.0034 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220207124653.htm

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