From Newsgroup: sci.bio.paleontology

An article in Science https://www.science.org/doi/10.1126/science.adv4635

Shishania is a chancelloriid and not a Cambrian mollusk

Abstract
The Cambrian evolutionary radiation is noted for its profusion of
bizarre and unfamiliar body forms, many of which illuminate the early
ancestry of major animal groups. The spine-covered fossil Shishania
aculeata (Cambrian Stage 4, Yunnan, China) has been interpreted as intermediate between mollusks and their lophotrochozoan ancestors. Our
new material challenges this interpretation. We propose taphonomic explanations for apparent molluscan features and instead identify
prominent anatomical similarities to coeval chancelloriids from nearby
strata. Our reinterpretation of Shishania as an early-diverging
chancelloriid helps to consolidate a model for the early evolution of
this enduringly problematic group of sponge-like metazoans.

Typical of rapid evolutionary expansions into unpopulated or recently
vacates ecospaces, Chancelloriids (and Shishania) are short-lived
organisms of uncertain affinities. They have been linked to both
sponges or halkieriids.
--- Synchronet 3.21d-Linux NewsLink 1.2

From Newsgroup: sci.bio.paleontology

On 5/9/25 8:57 AM, erik simpson wrote:

An article in Science https://www.science.org/doi/10.1126/science.adv4635

Shishania is a chancelloriid and not a Cambrian mollusk

Abstract
The Cambrian evolutionary radiation is noted for its profusion of
bizarre and unfamiliar body forms, many of which illuminate the early ancestry of major animal groups. The spine-covered fossil Shishania
aculeata (Cambrian Stage 4, Yunnan, China) has been interpreted as intermediate between mollusks and their lophotrochozoan ancestors. Our
new material challenges this interpretation. We propose taphonomic explanations for apparent molluscan features and instead identify
prominent anatomical similarities to coeval chancelloriids from nearby strata. Our reinterpretation of Shishania as an early-diverging chancelloriid helps to consolidate a model for the early evolution of
this enduringly problematic group of sponge-like metazoans.

Typical of rapid evolutionary expansions into unpopulated or recently vacates ecospaces, Chancelloriids (and Shishania) are short-lived
organisms of uncertain affinities.-a They have been linked to both
sponges or halkieriids.

And there's a big problem with fossils: you can't always tell a sponge
from a lophotrochozoan.
--- Synchronet 3.21d-Linux NewsLink 1.2