#mollusk

Corolla ovata

A sea butterfly that lives in temperate and warm waters of all oceans. It is an elegant swimmer that feeds with a mucous web in microplankton.

520-Million-Year-Old Fossil from China Fills Gap in Evolutionary History of Cephalopods

Paleontologists have identified the earliest-known cephalopod equipped with a siphuncle — a tubular extension of the mantle found in shelled cephalopods — pushing back the fossil record of this key evolutionary feature to the Early Cambrian, roughly 520 million years ago.

In a new study, the researchers examined 32 specimens of a previously unknown cephalopod species from the Shuijingtuo Formation in China. Named Eoceras shaanxiense, the animal lived in the Early Cambrian oceans approximately 520 million years ago. Millimeters in size, it had a straight, cone-shaped shell, a tilted opening, multiple internal walls, and a segmented tube running along the underside of the shell that connected to the chambers through tiny canals...

A unique cellular trick may explain octopus intelligence

A newly discovered change in ribosomal RNA makes protein production more precise, potentially safeguarding these cephalopods’ complex nervous systems

Now researchers have discovered another surprise in octopuses’ biology: a mutation, never documented in any other animal, that makes their cells remarkably accurate at creating proteins and that appeared just as they began evolving large nervous systems. “We can’t make a direct relation [between] a slight change in the accuracy of protein synthesis and so-called advanced intelligence,” says Nicholas Bellono, a Harvard University molecular biologist. But he notes that the timing “maps perfectly” with the emergence of sophisticated behaviors in octopuses. Bellono and his colleagues, who published their work today in Current Biology, stumbled upon this evolutionary innovation by accident. Co-lead author Richard Han, then a graduate student in the lab of Harvard Medical School cell biologist Amy Lee, was examining octopus RNA—the molecules that carry the genetic instructions that cells use to build proteins—when he noticed an unusual break in the genetic sequences that formed ribosomes, the cell’s protein-making machines. This stretch of ribosomal RNA (rRNA) is identical across every other animal that’s been studied, so the deviation jumped out at Han. “Finding a difference here was really unexpected for us,” he says...

black-velvet leatherleaf (belocaulus angustipes)

Submitted for classification by @five-red-feathers