Caryosyntrips: a radiodontan from the Cambrian of Spain, USA and Canada

Abstract

Caryosyntrips appendages have previously been reported from the Burgess Shale (Cambrian, Stage 5), British Columbia, Canada. New specimens of the genus are here reported from the Wheeler Formation (Cambrian, Drumian) and Langston Formation, Spence Shale Member (Cambrian, Stage 5), Utah, USA. The original Burgess Shale specimens are re-examined alongside the new specimens. Caryosyntrips is shown to have paired ventral spines on each podomere. Three species of Caryosyntrips are recognized: C. serratus Daley & Budd, C. camurus sp. nov. and C. durus sp. nov., differentiated by the overall shape of their appendages and arrangement of dorsal and ventral spines. These differences have potential implications for the feeding methods employed by different species of Caryosyntrips. A specimen collected from the upper Valdemiedes Formation of Spain (Cambrian, Stage 4), previously described as the lobopodian Mureropodia apae G amez Vintaned et al., is reinterpreted as a Caryosyntrips appendage. This identification is supported by the overall shape of the fossil, and the presence, orientation and length:width ratio of ventral spines. However the dorsal surface of the appendage is not well preserved, and the appendage and its ventral spines are larger than those of other known Caryosyntrips. Therefore it is left in open nomenclature as C. cf. camurus. These new finds increase the temporal range of Caryosyntrips (Cambrian Series 2, Stage 4 to Series 3, Drumian) and the geographical range to a new continent: Gondwana.

New suspension-feeding radiodont suggests evolution of microplanktivory in Cambrian macronekton

“…Amplectobelua 31 ), grasping-slicing (e.g. Caryosyntrips , Lyrarapax 27 , 32 ), or sediment sifting (e.g. Hurdia , Peytoia 23 ) functions.…”

First report of paired ventral endites in a hurdiid radiodont

“…Radiodonta, as large nektonic predators in Palaeozoic oceans, were an important member of marine ecosystems and played a pivotal role in structuring these early animal communities. These stem euarthropod predators with raptorial appendages [1,2], are a diverse and disparate group with over 25 species and 10 genera known from Africa, Australia, China, Europe, Greenland, and North America [3][4][5][6][7][8][9][10][11]. Recovered from deposits ranging from the Cambrian Series 2, Stage 3 to at least the Early Ordovician, and possibly even the Early Devonian, in age, these animals had body lengths from under 10 cm to around two meters [10][11][12][13][14][15][16][17].…”

Reply to Comment on "Aysheaia prolata from the Utah Wheeler Formation (Drumian, Cambrian) is a frontal appendage of the radiodontan Stanleycaris" with the formal description of Stanleycaris

“…The presence of lobopods is further problematic as the putative limbs have a much lower length/body ratio compared to all other Cambrian lobopodians, even smaller than that of Antennocanthopodia gra cilis from the Chengjiang biota (Ou et al 2011) or extant onychophorans (Haug et al 2012). By contrast, the length/width ratio of these features falls comfortably within the range observed in the ventral spines of Caryosyntrips appendages (Pates and Daley 2017).…”

“…Reply to Comment on "Aysheaia prolata from the Utah Wheeler Formation (Drumian, Cambrian) is a frontal appendage of the radiodontan Stanleycaris" with the formal description of Stanleycaris STEPHEN PATES, ALLISON C. DALEY, and JAVIER ORTEGA-HERNÁNDEZ As part of a comprehensive examination of all radiodontans from Cambrian localities in the USA, Pates et al (2017a, b) and Pates and Daley (2017) revised the taxonomic affinities of several described specimens. This included the reinterpretation of two putative lobopodians, one from the Wheeler Formation (Utah, USA) and one from the Valdemiedes Formation (Spain), as frontal appendages of the radiodontan genera Stanleycaris and Caryosyntrips respectively.…”

“…"Mureropodia" is not a lobopodian Gámez Vintaned and Zhuravlev (2018) argue that Pates and Daley (2017) ignored characters supporting a lobopodian affinity for "Mureropodia", such as the musculature, an antenniform appendage, retractable proboscis, claws and transverse telescopic structures. We find that these features consist of diagenetic artefacts, over-interpreted textures from the matrix, or preparation marks.…”