What is this platypus worm looking thing from Chengjiang?

[DardS8Br]

What is this thing? It looks like a platypus worm with spines coming out of its head. It’s from the Maotianshan Shale in Yunnan, China. What is it?

[DardS8Br]

I forgot to mention that it’s also about 1.5cm long

[Lone Hunter]

Geez I thought there was a misspelling or something in title but I probably would have called it the same thing  I'll second the what is it?

[Tidgy's Dad]

Some sort of priapulid worm? 

[BrennanThePaleoDude]

I was going to say worm until I noticed the seemingly sclerotized body segments typical of arthropods, especially with those small backwards facing spines along the "body" behind the "platypus bill" . I am under the impression it is the tail of a swimming arthropod 

[Fossildude19]

It's a shame it was destroyed by the poor prep. 

[westcoast]

Possibly the tail end of something broadly similar to Kylinxia. Could be significant. Pity about the prep job.

[piranha]

Alalcomenaeus and Leanchoilia are a couple of possibilities from Chengjiang. The tailpiece of Alalcomenaeus is broadly rounded and in this specimen the tailpiece appears to be missing the pointed tip so Leanchoilia illecebrosa looks like the best match.

 

 

"The telson has a wide and high anterior part, is articulated to the last segment, and is posteriorly extended into a flat surface, which is widest behind the middle and ends in a terminal acute angle (Fig. 29). At least anteriorly the flat surface is surrounded by sloping flanges. In the posterior part, the edges carry strong, tapering spines (Fig. 29)."

 

text and fig. 29 from:

 

Hou, X.G., Bergström, J. 1997
Arthropods of the Lower Cambrian Chengjiang Fauna, Southwest China.
Fossils and Strata, 45:1-116  PDF LINK

 

"Tailpiece – The tailpiece consists of a cylindrical part anteriorly and a dagger-shaped flap posteriorly (Fig. 2F). Each side of the tail flap has a row of postero-laterally pointed needle-like setae (Fig. 2F, see also fig. 29 in Hou & Bergström 1997). This description does not fit the appearance of a specimen illustrated by Hou & Bergström (1997, fig. 27C). Its tailpiece is broadly rounded caudally, not pointed as in L. illecebrosa, suggesting that the specimen is probably an Alalcomenaeus elegans (Luo & Hu in Luo, Hu, Chen, Zhang & Tao, 1999) (new name combination, for Apiocephalus elegans Luo & Hu in Luo, Hu, Chen, Zhang & Tao, 1999)."

text from:

 

Liu, Y., Hou, X.G., Bergström, J. 2007
Chengjiang Arthropod Leanchoilia illecebrosa (Hou, 1987) Reconsidered.
Geologiska Föreningens i Stockholm Förhandlingar, 129(3):263-272  PDF LINK

[piranha]

A more recent paper erected a new species Leanchoilia obesa for fig. 29 Leanchoilia illecebrosa (shown above: Hou & Bergström 1997, Liu et al. 2007)

 

"The new species, Leanchoilia obesa sp. nov., is distinguished from other species of Leanchoilia by an oval outline of the dorsal exoskeleton and a telson with a long basal region and long spines... ...dagger-shaped telson long, nearly one-fourth length of trunk; spineless basal part of telson relatively long in adult; triangular region of telson fringed with long spines."

 

 

 

He, Y.Y., Cong, P.Y., Liu, Y., Edgecombe, G.D., Hou, X.G. 2017

Telson Morphology of Leanchoiliidae (Arthropoda: Megacheira) Highlighted by a New Leanchoilia from the Cambrian Chengjiang Biota.

Alcheringa: An Australasian Journal of Palaeontology, 41(4):581-589  PDF LINK