#brachipoda

[gltzgghln]

30-day phyla challenge day 14: brachipoda no offense but brachipods are just weird bivalves i’m sorry that’s just how it is

[palaeopedia]

The Brachipoda, Heliomedusa (1994) Kingdom : Animalia

Early Cambrian (525 Ma)

3 cm long (size)

China (map)

This brachiopod is known as Heliomedusa orienta. The species is a relatively common member of the Chengjiang biota. The source of the specific name is easy to determine, but the reason is that the oval shape and redial patterning led the original describers to think it was a jellyfish.. The diversity of soft-tissue fossils is astonishing: algae, medusiforms, sponges, priapulids, annelid-like worms, echinoderms, arthropods (including trilobites), hemichordates, chordates, and the first agnathan fish make up just a small fraction of the total. Numerous problematic formsare known as well, some of which may have represented failed attempts at diversity that did not persist to the present day. Unlike most brachiopods, Heliomedusa lacked a pedicle, leading scientists to believe it layupon the surface of the sediment as an epifaunal filter feeder. Notice the fringe of setae thought to have served a sensory function. Note too the dark U-shaped structure contained within the shell. This is the lophophore, the structure by which the brachiopod circulated water for respiration and to extract food. Even the growth lines in the shell are readily discerned.