Traumatocrinus caudex DITTMAR, 1866

Taxonomy

Crinoid

Kingdom: Animalia
Phylum: Echinodermata
Class: Crinoidea
Order: Encrinida
Family: Incertae sedis
Genus: Traumatocrinus
Species: Traumatocrinus caudex
Author Citation DITTMAR, 1866

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Triassic
Sub Period: None
Epoch: Late
International Age: Carnian

Stratigraphy

Xiaowa Formation
Lower Xiaowa Member

Biostratigraphy

Conodont Zone Metapolygnathus nodosus

Provenance

Acquired by: Purchase/Trade

Location

Xiaowa
Guanling
Guizhou
China

• guanling
• guizhou
• triassic
• traumatocrinus

Comments

This species is also known under the name T. hsui. The discussion about whether this is T. hsui or T. caudex seems to be still going on.

Diagnosis from Hagdorn et al. 2015, p. 16: "Cup cryptodicyclic with five infrabasals and five basals; basals almost completely concealed in column pit; radials with low trapezoidal exposed aboral side and outward inclined facet with strings of granules separated by grooves (fossulae); radial articular facet and all brachial articulations ligamentary (granosyzygial). Primibrachial 2 axillary, secundibrachial 2 axillary in juveniles, in adults second arm branching after indefinite number of irregularly biserial secundibrachials. In juveniles four isotomously branching arms which constitute the 20 major arms of adults. In adults, indefinite number of endotomously branching tertiary armlets; arm branching starting at outer arms of each ray. Armlets may branch again at distal axillaries with aboral inflation or spine. Arms biserial. Brachial articulations granosyzygial with strings of granules separated by fossulae opening at equidistant circular pores along aboral sutures. Arms pinnulate after second branching. First pinnular shorter than second, with muscular articulation to brachial. Proximal and medial pinnulars with serrated margins, distal pinnulars with blade-shaped spines. Tegmen with polygonal plates, anal tube short with polygonal, aborally inflated plates around anal opening. Functional cup enlarged by means of tegminal plates extending between proximal arms, forming polygonal interbrachials and five large rhomboidal interradials inserting between interradial sutures. Interradials already present in juveniles of less than 10 mm crown height. No mouth visible; small perforated tegminal platelets at the base of free arms. Column long to very long, proximally with distinct nodals, noditaxes with up to four series of internodals. Nodals without cirri. Columnals low, circular to elliptical, granosyzygial, with multiradiate rows of granules that may be arranged as sets of chevrons; number of granule rows increasing toward the margin by bifurcation and intercalation. Intercolumnal grooves (fossulae) between granule rows with equidistant circular pore openings leading to sets of channels (tubuli) running through proximal and medial column; set of five primary tubuli surrounding lumen of central canal. Terminal column with extremely low columnals with articulated anastomosing radicular cirri, articulate facets of cirrals multiradiate."

Identified by oilshale.

References:

Xiaofeng, W., Hagdorn, H. & Chuanshang, W. (2006 09 12) Pseudoplanktonic lifestyle of the Triassic crinoid Traumatocrinus from Southwest China. Lethaia , Vol. 39, pp. 187-193. Oslo. ISSN 0024-1164.
Wang et al,. (2003) Restudy of the crinoids Traumatocrinus of the Guanling biota Guizhou. Geological Bulletin of China Vol. 22 No. 4, p. 248-253.

Hagdorn, Hans; Wang, Xiao-Feng (2015). The pseudoplanktonic crinoid Traumatocrinus from the Late Triassic of Southwest China — Morphology, ontogeny, and taphonomy. Palaeoworld, (), S1871174X15000414–. doi:10.1016/j.palwor.2015.05.006