Return to David's theory of evolution PART 2: more Cambrian (Evolution)

by David Turell , Sunday, July 10, 2022, 01:51 (865 days ago) @ David Turell

Note the advanced complexity of this very large arthropod fossil:

http://www.sci-news.com/paleontology/balhuticaris-voltae-10983.html?utm_source=feedburn...

"Balhuticaris voltae swam in the oceans of the Cambrian period approximately 506 million years ago.

"At 24.5 cm (9.6 inches) long, the ancient animal is one of the largest Cambrian arthropods and the biggest bivalved arthropod known to date, with the closest being Nereocaris exilis and Tuzoia.

"Balhuticaris voltae was likely a type of hymenocarine, a group of Cambrian arthropods that possessed bivalved carapaces and looked superficially like shrimps.

“'Cambrian bivalved arthropods are a group of arthropods characterized by their cephalothoracic bivalved carapaces,” said University of Toronto paleontologists Alejandro Izquierdo-López and Jean-Bernard Caron.

“'Many bivalved arthropods are known only from isolated carapaces, but fossils with soft tissue preservation are revealing an increasingly complex polyphyletic group, mostly comprising the stem-group euarthropod Isoxyidae and the Hymenocarina.”

***

"Balhuticaris voltae had an extremely elongated and multisegmented body bearing ca. 110 pairs of homonomous biramous limbs.

"The animal’s unusual carapace resembled an arch; it covered only the frontalmost section of the body but extended ventrally beyond the legs.

"It had a complex sensory system and was probably an active swimmer thanks to its powerful paddle-shaped exopods and a long and flexible body.

“'With a total of 110 post-cephalic segments, Balhuticaris voltae has the highest number of segments recorded among Cambrian arthropods,” the researchers said.

***

“'Balhuticaris voltae is one of the biggest fully-preserved animals from the Burgess Shale and the Cambrian,” the scientists said.

“'The increasing ecological complexity of the Cambrian has long been recognized based on its planktonic communities or the filling of the pelagic zone and species such as Balhuticaris voltae, thus, not only exemplify how gigantism in the Cambrian occurred in a wider number of groups than Radiodonta but also exemplify this increasing complexity of the Cambrian ecosystems.'”

Comment: these active swimmers were coordinated by having eyes, brains, widespread nervous control over muscles. They had full digestive systems to handle what they ingested. WE can assume there was some sort of renal system based on what organs arthropods have today. All of this complexity appeared only 410,000 years removed from the very simple Ediacaran frond-like sessile forms. And dhw proposes 30,000 generational adaptations could do this. Really?