Pelmatozoan arms from the mid-Cambrian of Australia: bridging the gap between brachioles and brachials? Comment: there is no bridge

Guensburg, Thomas E.; Mooi, Rich; Sprinkle, James; David, Bruno; Lefèbvre, Bertrand

doi:10.1111/j.1502-3931.2010.00220.x

Cited by 24 publications

(30 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They displayed a globular theca with five recumbent ambulacra constructed with large, biserial and exposed flooring plates and large, simple or complex cover plates. All known species have a polyplated stem to elevate the theca above the substrate, but their attachment mechanism is still unknown (Mintz 1970;Smith and Jell 1990;Guensburg and Sprinkle 1994;Guensburg et al 2010). …”

Section: Introductionmentioning

confidence: 99%

Ontogeny, functional morphology, and comparative morphology of lower (Stage 4) and basal middle (Stage 5) Cambrian gogiids, Guizhou Province, China

Parsley

2012

J. Paleontol.

View full text Add to dashboard Cite

Three gogiid eocrinoids, numbering in the thousands of specimens, are well known from the lower Cambrian (Stage 4) Balang Formation (Guizhoueocrinus yui) and basal middle Cambrian (Stage 5) Kaili Formation (Kaili Biota) (Sinoeocrinus lui and Globoeocrinus globulus) that resided on the Yangtze-South China Plate (modern Guizhou Province, China). In each species a complete ontogenetic sequence, using thecal height (TH) as a scale, juvenile stage (early, middle, and late substages), mature stage (early, middle, and late substages), and a gerontic stage can be identified. Sutural pores appeared in an orderly sequence; below the ambulacrals, above the stalk and generally over the theca, in that order. In younger species their emplacement and growth was commonly precocious relative to G. yui. Also, their shape ranges from circular to oval to triangular in a single growth sequence, after the establishment of the 2-1-2 pattern; brachioles were added in series of five and were also precocious in time of occurrence in younger species. Thecae in younger species tend to retain juvenile aspects relative to G. yui. All of these species lived in outer shelf settings in fine-grained, organic-rich siliciclastics.

show abstract

Section: Introductionmentioning

confidence: 99%

Ontogeny, functional morphology, and comparative morphology of lower (Stage 4) and basal middle (Stage 5) Cambrian gogiids, Guizhou Province, China

Parsley

2012

J. Paleontol.

View full text Add to dashboard Cite

show abstract

“…Estas estructuras nacen normalmente de facetas braquiolares, que conectan las braquiolas con los surcos alimenticios y que a su vez convergen en la boca. Existen numerosas diferencias morfológicas entre las braquiolas de los blastozoos y los brazos de los crinoideos, por lo que su posible homología sigue siendo un tema muy discutido (ver resumen en Guensburg & Sprinkle, 2007;Guensburg et al 2010). La teca forma el cuerpo principal del organismo y se compone de placas organizadas en ciclos o irregularmente dispuestas.…”

Section: Clase Eocrinoideaunclassified

Equinodermos del Cámbrico de España: situación actual de las investigaciones y perspectivas futuras

Zamora

2011

Estud. geol.

View full text Add to dashboard Cite

RESUMENEn este trabajo se presenta una revisión histórica de todos los equinodermos cámbricos descubiertos en España, desde su primer hallazgo a finales del siglo XIX y las técnicas actuales que se utilizan para su estudio.El muestreo sistemático de nuevas localidades cámbricas del Norte de España y la revisión de otras ya conocidas, ha proporcionado más de 2.000 ejemplares de equinodermos. En total se han reconocido taxones pertenecientes a cinco clases: Cincta, Eocrinoidea, Edrioasteroidea, Stylophora y Ctenocystoidea, que muestran la mayor diversidad para este periodo en Gondwana.Estos hallazgos muestran que los equinodermos alcanzaron su primer pico de diversidad durante el Cámbrico medio. Esto, unido a la amplia distribución paleobiogeográfica de algunos clados, nos advierte de un origen para muchos grupos en el Cámbrico inferior, donde sólo unos pocos taxones han sido descritos a nivel mundial. Por último se dan algunas ideas de hacia dónde se podrían dirigir los esfuerzos en este campo de conocimiento.Palabras clave: equinodermos, Cámbrico, Gondwana, España, revisión, diversidad ABSTRACT This paper reviews all finds of Cambrian echinoderms from Spain since their first discovery in the XIX century. Recent research techniques used for the study of echinoderms are also described, providing a guide for procedure.Sampling in new fossiliferous localities from the Cambrian of North Spain and the review of classic ones has yielded more than 2,000 echinoderm fossils. These include species belonging to five major classes, Cincta, Eocrinoidea, Edrioasteroidea, Stylophora and Ctenocystoidea, which show the highest diversity reported from Gondwana.These results suggest that echinoderms underwent major diversification during the middle Cambrian, with many groups more widely distributed than previously thought. These arguments suggest that many classes originated in the lower Cambrian where only a few taxa have been described. Finally, I offer some suggestions about where research efforts need to be focussed for a better knowledge of Cambrian echinoderm faunas in Gondwana.

show abstract

“…For this reason, they are described separately in the following section. These plates also exhibit characters known from both blastozoan and crinozoan appendages (Clausen et al 2009(Clausen et al , 2012Guensburg et al 2010). The diagnostic features or apomorphies of both groups are debatable, since the plasticity of appendage structure of Cambrian pelmatozoans has been convincingly illustrated (Zamora and Smith 2011). Brachial, unbranched ossicles (brachitaxial) Material.-Five plates, including SMNH Ec 31506-31509, from sample 7/70.…”

Section: Stratigraphic and Geographic Range-problematic Sclerites Ofmentioning

confidence: 99%

“…However, the uniserial and brachiolar plates clearly differ in terms of the organization of the oral food groove and lateral walls. Uniserial brachials are also described from the middle Cambrian of Australia (Clausen et al 2009) and Laurentia (Clausen and Peel 2012), but their affinity is still debated (see Guensburg et al 2010). Uniserial plates are also known from Ordovician blastozoans (e.g., Rhipidocystites; Guensburg et al 2010) and paracrinoids (Parsley and Mintz 1975).…”

Section: Stratigraphic and Geographic Range-problematic Sclerites Ofmentioning

confidence: 99%

“…Uniserial brachials are also described from the middle Cambrian of Australia (Clausen et al 2009) and Laurentia (Clausen and Peel 2012), but their affinity is still debated (see Guensburg et al 2010). Uniserial plates are also known from Ordovician blastozoans (e.g., Rhipidocystites; Guensburg et al 2010) and paracrinoids (Parsley and Mintz 1975). However, as in Rhipidocystites, blastozoan uniserial brachioles have the morphology of two fused brachiolar plates, most probably representing biserial arrangement with a "suppressed" biserial suture ( tripartite oral-groove and one undulose articulation-facet, SMNH Ec 31506; E 1 , axial view of articulation facet; E 2 , oral view showing the flat (to the base) and undulose (to the top) articulation surfaces; E 3 , aboral view.…”

Section: Stratigraphic and Geographic Range-problematic Sclerites Ofmentioning

confidence: 99%

See 1 more Smart Citation

A bradoriid and brachiopod dominated shelly fauna from the Furongian (Cambrian) of Västergötland, Sweden

et al. 2013

View full text Add to dashboard Cite

A small assemblage of shelly fossils, dominated by the brachiopod Treptotreta jucunda and the bradoriid arthropod Mongolitubulus aspermachaera new species is described from a Furongian limestone of Västergötland, south-central Sweden. Mongolitubulus aspermachaera is represented in the assemblage by individual valves and numerous, ornamented spines. Valves and spines share identical ornament and microstructure leaving no doubt that the isolated spines were once attached to the bradoriid valves. Mongolitubulus aspermachaera adds to the increasing list of spinose Cambrian bradoriid arthropods, and Mongolitubulidae new family is erected here to incorporate the genera Mongolitubulus, Tubuterium and Spinospitella. Mongolitubulus aspermachaera represents the youngest member of the new family and supplements the biodiversity of bradoriids in the Furongian, an interval when bradoriid diversity is considered to be very much on the decline. The brachiopod Treptotreta jucunda described predominantly from the ‘middle' to ‘late' Cambrian of Australia is here documented for the first time from outside Gondwana, dramatically extending the biogeographical range of the species. Other elements of the faunal assemblage include typical Baltic Furongian representatives, such as the trilobite Parabolina, the agnostoid Agnostus and the phosphatocopids Hesslandona and Vestrogothia.

show abstract

Pelmatozoan arms from the mid-Cambrian of Australia: bridging the gap between brachioles and brachials? Comment: there is no bridge

Cited by 24 publications

References 22 publications

Ontogeny, functional morphology, and comparative morphology of lower (Stage 4) and basal middle (Stage 5) Cambrian gogiids, Guizhou Province, China

Ontogeny, functional morphology, and comparative morphology of lower (Stage 4) and basal middle (Stage 5) Cambrian gogiids, Guizhou Province, China

Equinodermos del Cámbrico de España: situación actual de las investigaciones y perspectivas futuras

A bradoriid and brachiopod dominated shelly fauna from the Furongian (Cambrian) of Västergötland, Sweden

Contact Info

Product

Resources

About