Hurdiidae Explained
Hurdiidae (synonymous with the previously named Peytoiidae[1]) is an extinct cosmopolitan family of radiodonts, a group of stem-group arthropods, which lived during the Paleozoic Era. It is the most long-lived radiodont clade, lasting from the Cambrian period to the Devonian period.
Description
Hurdiidae is characterized by frontal appendages with distal region composed of 5 subequal blade-like endites, alongside the enlarged head carapaces and tetraradial mouthpart (oral cone).
The frontal appendages of hurdiids have a distinctive morphology, with the appendage of most species bearing five equally-sized elongate blade-like ventral spines known as endites. Subsequent podomeres were reduced in size and with only small endites or none. Each podomere bore only a single endite, unlike other radiodonts, in which the endites were paired. In most species, the endites were curved medially, so that the appendages formed a basket-like structure. Some hurdiids had greater numbers of endites, with Cordaticaris bearing seven endites of equal length. Ursulinacaris is unique among hurdiids in bearing paired endites, which is likely a transitional form between the appendage of other radiodonts and that of hurdiids.
Hurdiids exhibited a wide range of body size. The smallest known hurdiid specimen, of an unnamed species, is estimated to have had a body length of 6mm15mm, but it is not known whether this specimen was juvenile or adult. Aegirocassis, the largest known hurdiid, was over 2m (07feet) long, comparable in size to the largest known arthropods.
Paleobiology
The majority of hurdiids appear to have been predators that fed by sifting sediment with their frontal appendages, but some members, like Aegirocassis, Pseudoangustidontus, and possibly Cambroraster were suspension feeders.[2]
Distribution
Hurdiids had a global distribution. The earliest known hurdiid in the fossil record is Peytoia infercambriensis, which lived during the third age of the Cambrian in what is now the country of Poland. The group increased in diversity during the Miaolingian epoch. Post-Cambrian records of the group are rare, but the group lasted into the Devonian period, with the last known taxon being the Emsian Schinderhannes bartelsi from what is now Germany.
Classification
Hurdiidae is classified within Radiodonta, a clade of stem-group arthropods. Hurdiidae is defined phylogenetically as the most inclusive clade containing Hurdia victoria but not Amplectobelua symbrachiata, Anomalocaris canadensis, or Tamisiocaris borealis. Some authors have argued that Peytoiidae, which was named by Conway Morris and Robison, 1982, has priority over Hurdiidae, and that Hurdiidae has "yet to be properly established following ICZN standards".
The phylogeny of hurdiids, accompanying the description of the hurdiids Aegirocassis benmoulae, Titanokorys gainesii, and the analyzation of Stanleycaris hirpex as follows:
Species include
Tauricornicaris was previously considered as a member of hurdiid, but later reinterpreted as euarthropod tergites.[6] [7]
Zhenghecaris is originally described as a thylacocephalan, but it is later considered as hurdiid dorsal carapace.[8] [9] However, placement is questioned by some researchers, because classification as radiodont is majorly based on characters of Tauricornicaris.
Schinderhannes was originally described as stem-arthropod which have both characters of euarthropods and radiodonts, this interpretation was denied and most researchers agree that is hurdiid radiodont.[10] [11] [12] [13] [14] [15] [16] [17] There are some researchers who questioned its classification as hurdiid.[18] [19]
Huangshandongia yichangensis, Liantuoia inflata[20] and Proboscicaris hospes[21] may represent species of Hurdia.[22] [23]
Notes and References
- McCall . Christian R.A. . 2023-12-13 . A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada . Journal of Paleontology . 97 . 5 . en . 1009–1024 . 10.1017/jpa.2023.63 . 2023JPal...97.1009M . 266292707 . 0022-3360.
- De Vivo . Giacinto . Lautenschlager . Stephan . Vinther . Jakob . 2021-07-28 . Three-dimensional modelling, disparity and ecology of the first Cambrian apex predators . Proceedings of the Royal Society B: Biological Sciences . en . 288 . 1955 . 20211176 . 10.1098/rspb.2021.1176 . 0962-8452 . 8292756 . 34284622.
- Pates S, Lerosey-Aubril R, Daley AC, Kier C, Bonino E, Ortega-Hernández J. 2021. The diverse radiodont fauna from the Marjum Formation of Utah, USA (Cambrian: Drumian) PeerJ 9:e10509 https://doi.org/10.7717/peerj.10509
- Caron . Jean-Bernard . Moysiuk . Joe . 2021 . A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity . R. Soc. Open Sci. . 8 . 210664 . 210664 . 10.1098/rsos.210664 . 34527273 . 8424305 . 2021RSOS....810664C .
- Potin . G. J.-M. . Gueriau . P. . Daley . A. C. . 2023 . Radiodont frontal appendages from the Fezouata Biota (Morocco) reveal high diversity and ecological adaptations to suspension-feeding during the Early Ordovician . Frontiers in Ecology and Evolution . 11 . 1214109 . 10.3389/fevo.2023.1214109 . free.
- Guo . J. . Pates . S. . Cong . P. . Daley . A. . Edgecombe . G. . Chen . T. . Hou . X. . 2018 . A new radiodont (stem Euarthropoda) frontal appendage with a mosaic of characters from the Cambrian (Series 2 Stage 3) Chengjiang biota . Papers in Palaeontology . en . 5 . 1 . 99 . 10.1002/spp2.1231 . 2019PPal....5...99G . 2056-2799.
- Cong . Pei-Yun . Edgecombe . Gregory D. . Daley . Allison C. . Guo . Jin . Pates . Stephen . Hou . Xian-Guang . 2018 . Zhang . Xi-Guang . New radiodonts with gnathobase-like structures from the Cambrian Chengjiang biota and implications for the systematics of Radiodonta . Papers in Palaeontology . en . 4 . 4 . 605–621 . 10.1002/spp2.1219 . 2018PPal....4..605C . 2056-2799.
- Pates . Stephen . Daley . Allison C. . Butterfield . Nicholas J. . 2019-06-11 . First report of paired ventral endites in a hurdiid radiodont . Zoological Letters . 5 . 1 . 18 . 10.1186/s40851-019-0132-4 . free . 2056-306X . 6560863 . 31210962.
- Moysiuk . J. . Caron . J.-B. . 2019-08-14 . A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources . Proceedings of the Royal Society B: Biological Sciences . en . 286 . 1908 . 20191079 . 10.1098/rspb.2019.1079 . 0962-8452 . 6710600 . 31362637.
- Vinther . Jakob . Stein . Martin . Longrich . Nicholas R. . Harper . David A. T. . 2014 . A suspension-feeding anomalocarid from the Early Cambrian . Nature . en . 507 . 7493 . 496–499 . 2014Natur.507..496V . 10.1038/nature13010 . 1476-4687 . 24670770 . 205237459 . free . 1983/88f89453-e81f-4767-a74d-1794c33e6b34.
- Cong . Peiyun . Ma . Xiaoya . Hou . Xianguang . Edgecombe . Gregory D. . Strausfeld . Nicholas J. . 2014 . Brain structure resolves the segmental affinity of anomalocaridid appendages . Nature . en . 513 . 7519 . 538–542 . 2014Natur.513..538C . 10.1038/nature13486 . 1476-4687 . 25043032 . 4451239 .
- Van Roy . Peter . Daley . Allison C. . Briggs . Derek E. G. . 2015 . Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps . Nature . en . 522 . 7554 . 77–80 . 2015Natur.522...77V . 10.1038/nature14256 . 1476-4687 . 25762145 . 205242881 .
- Lerosey-Aubril . Rudy . Pates . Stephen . 2018-09-14 . New suspension-feeding radiodont suggests evolution of microplanktivory in Cambrian macronekton . Nature Communications . en . 9 . 1 . 3774 . 2018NatCo...9.3774L . 10.1038/s41467-018-06229-7 . 2041-1723 . 6138677 . 30218075. Dryad Data
- Liu . Jianni . Lerosey-Aubril . Rudy . Steiner . Michael . Dunlop . Jason A . Shu . Degan . Paterson . John R . 2018-06-01 . Origin of raptorial feeding in juvenile euarthropods revealed by a Cambrian radiodontan . National Science Review . 5 . 6 . 863–869 . 10.1093/nsr/nwy057 . 2095-5138. free .
- Moysiuk . Joseph . Caron . Jean-Bernard . 2021 . Exceptional multifunctionality in the feeding apparatus of a mid-Cambrian radiodont . Paleobiology . en . 47 . 4 . 704–724 . 10.1017/pab.2021.19 . 2021Pbio...47..704M . 0094-8373. free .
- Moysiuk . Joseph . Caron . Jean-Bernard . 2022 . A three-eyed radiodont with fossilized neuroanatomy informs the origin of the arthropod head and segmentation . Current Biology . 32 . 15 . 3302–3316.e2 . 10.1016/j.cub.2022.06.027 . 35809569 . 2022CBio...32E3302M . 0960-9822.
- Zeng . Han . Zhao . Fangchen . Zhu . Maoyan . 2023-01-06 . Innovatiocaris, a complete radiodont from the early Cambrian Chengjiang Lagerstätte and its implications for the phylogeny of Radiodonta . Journal of the Geological Society . en . 180 . 1 . 10.1144/jgs2021-164 . 2023JGSoc.180..164Z . 0016-7649.
- Zhu, X. . Lerosey-Aubril, R. . Ortega-Hernández, J. . 2021 . Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae . . 9 . e11800 . 10.7717/peerj.11800 . 8312493 . 34386302 . free . en.
- Potin . Gaëtan J.-M. . Daley . Allison C. . 2023 . The significance of Anomalocaris and other Radiodonta for understanding paleoecology and evolution during the Cambrian explosion . Frontiers in Earth Science . 11 . 2023FrEaS..1160285P . 10.3389/feart.2023.1160285 . 2296-6463 . free.
- Zhilin . Cui . Shicheng . Huo . 1990 . 鄂西下寒武统甲壳类化石新发现 . Acta Palaeontologica Sinica.
- Chlupač . Ivo . Kordule . Vratislav . 2002 . Arthropods of Burgess Shale type from the Middle Cambrian of Bohemia (Czech Republic) . Bulletin of the Czech Geological Survey . 77 . 3 . 167–182.
- Daley . Allison C. . Budd . Graham E. . Caron . Jean-Bernard . 2013 . Morphology and systematics of the anomalocaridid arthropod Hurdia from the Middle Cambrian of British Columbia and Utah . Journal of Systematic Palaeontology . en . 11 . 7 . 743–787 . 10.1080/14772019.2012.732723 . 2013JSPal..11..743D . 1477-2019.
- Sun . Zhixin . Zeng . Han . Zhao . Fangchen . 2020 . A new middle Cambrian radiodont from North China: Implications for morphological disparity and spatial distribution of hurdiids . Palaeogeography, Palaeoclimatology, Palaeoecology . 558 . 109947 . 10.1016/j.palaeo.2020.109947 . 2020PPP...55809947S . 0031-0182.