An eight-branched spiral

Eoandromeda octobrachiata may or may not set the tree of life wobbling but it has certainly been given a beautiful name, inspired by the fact that its body plan resembles the spiral galaxy Andromeda.

Deep dive

I wrote in an earlier post that few creatures are as strange as the Ediacarian biota. One candidate may be Paleodictyon nodosum (perhaps a xenophyophore). The only known visible feature associated with this being:

consists of tiny holes arranged in six-sided patterns that look curiously like the hearts of Chinese checkers boards. [Peter A. Rona] has photographed thousands of the hexagons and found that large ones have 200 or 300 holes.


Dr Rona's inability to catch the creature itself means that even though scientists have given it the fossil’s name, they still vigorously debate what it is. The main question is whether the hexagonal patterns are burrows or body parts, vacant residences or animal remains.

-- from Diving deep for a living fossil.

Symmetry of gliding reflection

Jorge Luis Borges noted that Sir Thomas Browne dismissed the Amphisbaena, a two-headed snake, because there could be no creature without a bottom, top, front, back, left and right.

I can find few creatures, real or imaginary, stranger than the Ediacarian biota (given, for now, that we take them to be animals and not something else).

Trilobozoa, for example, had triradial symmetry, while Yorgia had symmetry of gliding reflection.

What would Browne and Borges have made of them?



another image here.