Hurdia

Last updated

Hurdia
Temporal range: Mid Cambrian, 518–505  Ma
20210619 Hurdia.png
Reconstruction of H. victoria (top) and H. triangulata
Hurdia disarticulated assemblages.jpg
Disarticulated fossils
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class:† Dinocaridida
Order:† Radiodonta
Family:† Hurdiidae
Genus:† Hurdia
Walcott, 1912
Type species
†Hurdia victoria
Walcott, 1912
Other species
  • †H. triangulataWalcott, 1912
  • †?H. hospesChlupach and Kordule, 2002
Synonyms
  • †?Huangshandongia yichangensisShicheng and Zhilin, 1990
  • †?Liantuoia inflataShicheng and Zhilin, 1990

Hurdia is an extinct genus of hurdiid radiodont that lived 505 million years ago during the Cambrian Period. Fossils have been found in North America, China and the Czech Republic.

Contents

Description

Hurdia was one of the largest organisms in the Cambrian oceans, H. victoria reached between 18.3–30.5 cm (7.2–12.0 in) in length, while H. triangulata reached up to just 8.1 cm (3.2 in) long. [1] Its head bore a pair of frontal appendages. These frontal appendages had 9 or more rarely 10 or 11 segments/podomeres, which were approximately rectangular and decreased in size towards the end of the appendage. The upper surface of the appendage was convexly curved. Podomeres 2 to 6 bore long downward pointing spines (ventral spines) with forward-curving tips. These ventral spines themselves bore up to 9 equally spaced forward-facing spines dubbed auxiliary spines, with podomeres 7 and 8 bearing shorter, smooth forward curving spines. The frontal appenages were used to bring food to its ring-shaped mouth (oral cone), in which four large plates are present, with inner rows of spines inside the main cone. [2] Like other hurdiids, Hurdia bore a large frontal carapace protruding from its head composed of three sclerites: a central component known as the H-element and two lateral components known as P-elements. Originally, it is estimated that body flaps ran along the sides of the organisms, from which large gills were suspended. [3] However, anatomy of Aegirocassis clarified that Hurdia had both ventral and dorsal flaps, and gills were on trunk segments. [4]

Ecology

Hurdia is either suggested to have used its frontal appendages to sift small prey from sediment, or to have used them as a trap to capture larger benthic (seafloor dwelling) prey. [5]

Distribution

Hurdia had cosmopolitan distribution; two described species has been recovered from the Burgess Shale in British Columbia, Canada. In addition, H. victoria is also known from the Spence Shale in Utah, USA. [6] Unnamed species are known from Qingjiang biota in Hubei, China, Pioche Shale in Nevada, USA, and Wheeler Shale in Utah, USA. [6] [7] Huangshandongia yichangensis and Liantuoia inflata from the Shuijingtuo Formation in Hubei, China, and Proboscicaris hospes from the Jince Formation of the Czech Republic (which is identified as Hurdia hospes in some papers [8] ), and unnamed fossil from Ordovician Fezouata Formation could represent species of Hurdia as well. [3] [2]

Taxonomic history

Hurdia was named in 1912 by Charles Walcott, with two species, the type species H. victoria and a referred species, H. triangulata. [9] The genus name refers to Mount Hurd. [9] It is possible that Walcott had described a specimen the year prior as Amiella, but the specimen is too fragmentary to identify with certainty, so Amiella is a nomen dubium . [10] Walcott's original specimens consisted only of H-elements of the frontal carapace, which he interpreted as being the carapace of an unidentified type of crustacean. P-elements of the carapace were described as a separate genus, Proboscicaris, in 1962.

In 1996, then-curator of the Royal Ontario Museum Desmond H. Collins erected the taxon Radiodonta to encompass Anomalocaris and its close relatives, and included both Hurdia and Proboscicaris in the group. [11] He subsequently recognized that Proboscicaris and Hurdia were based on different parts of the same animal, and recognized that a specimen previously assigned to Peytoia was also a specimen of the species. [10] He presented his ideas in informal articles, [12] [13] and it was not until 2009, after three years of painstaking research, that the complete organism was reconstructed. [3] [14] [15] [16]

Sixty-nine specimens of Hurdia are known from the Greater Phyllopod bed, where they comprise 0.13% of the community. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Dinocaridida</span> Extinct class of basal arthropods

Dinocaridida is a proposed fossil taxon of basal arthropods, which flourished during the Cambrian period and survived up to the Early to Middle Ordovician. The putative Early Devonian member Schinderhannes bartelsi has been considered questionable by some researchers.

<i>Anomalocaris</i> Extinct genus of cambrian radiodont

Anomalocaris is an extinct genus of radiodont, an order of early-diverging stem-group arthropods.

<i>Peytoia</i> Extinct genus of radiodont

Peytoia is a genus of hurdiid radiodont, an early diverging order of stem-group arthropods, that lived in the Cambrian period, containing two species, Peytoia nathorsti from the Miaolingian of Canada and Peytoia infercambriensis from Poland, dating to Cambrian Stage 3. Its two frontal appendages had long bristle-like spines, it had no fan tail, and its short stalked eyes were behind its large head.

<i>Peytoia infercambriensis</i> Extinct species of arthropod

Peytoia infercambriensis is a species of hurdiid radiodont in the genus Peytoia.

<i>Schinderhannes bartelsi</i> Extinct species of radiodont

Schinderhannes bartelsi is a species of stem-group arthropod, possibly a hurdiid radiodont (anomalocaridid), known from one specimen from the Lower Devonian Hunsrück Slates. Its discovery was astonishing because the latest definitive radiodonts were known only from the Early Ordovician, at least 66 million years earlier than this taxon. Although some phylogenetic analyses found support for its taxonomic placement as a hurdiid radiodont, other researchers have questioned these assignments.

<i>Isoxys</i> Genus of extinct arthropods

Isoxys is a genus of extinct bivalved Cambrian arthropod; the various species of which are thought to have been freely swimming predators. It had a pair of large spherical eyes, and two large frontal appendages used to grasp prey.

<span class="mw-page-title-main">Radiodonta</span> Extinct order of basal arthropods

Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two originally refer to the family Anomalocarididae, which previously included all species of this order but is now restricted to only a few species. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and used for a variety of functions. Radiodonts included the earliest large predators known, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa Anomalocaris canadensis, Hurdia victoria, Peytoia nathorsti, Titanokorys gainessii, Cambroraster falcatus and Amplectobelua symbrachiata. The latest surviving members include the Aegirocassisinae from the Early Ordovician of Morocco. The putative Early Devonian member Schinderhannes bartelsi from Germany has been considered questionable by some researchers.

<i>Stanleycaris</i> Extinct genus of basal hurdiid radiodonts

Stanleycaris is an extinct, monotypic genus of hurdiid radiodont from the middle Cambrian (Miaolingian). The type species is Stanleycaris hirpex. Stanleycaris was described from the Stephen Formation near the Stanley Glacier and Burgess Shale locality of Canada, as well as Wheeler Formation of United States. The genus was characterized by the rake-like frontal appendages with robust inner spines.

<i>Caryosyntrips</i> Extinct genus of arthropod

Caryosyntrips ("nutcracker") is an extinct genus of stem-arthropod which known from Canada, United States and Spain during the middle Cambrian.

<i>Aegirocassis</i> Extinct genus of radiodonts

Aegirocassis is an extinct genus of giant radiodont arthropod belonging to the family Hurdiidae that lived 480 million years ago during the early Ordovician in the Fezouata Formation of Morocco. It is known by a single species, Aegirocassis benmoulai. Van Roy initiated scientific study of the fossil, the earliest known of a "giant" filter-feeder discovered to date. Aegirocassis is considered to have evolved from early predatory radiodonts. This animal is characterized by its long, forward facing head sclerite, and the endites on its frontal appendages that bore copious amounts of baleen-like auxiliary spines. This animal evolving filter-feeding traits was most likely a result of the Great Ordovician Biodiversification Event, when environmental changes caused a diversification of plankton, which in turn allowed for the evolution of new suspension feeding lifeforms. Alongside the closely related Pseudoangustidontus, an unnamed hurdiid from Wales, the middle Ordovician dinocaridid Mieridduryn, and the Devonian hurdiid Schinderhannes this radiodont is one of the few dinocaridids known from post-Cambrian rocks.

<span class="mw-page-title-main">Hurdiidae</span> Extinct family of arthropods

Hurdiidae 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, with definitive members lasting from the Cambrian to the earliest Ordovician period. The putative Early Devonian member Schinderhannes bartelsi has been considered questionable by some researchers.

<i>Ramskoeldia</i> Extinct genus of Amplectobeluid radiodont

Ramskoeldia is a genus of amplectobeluid radiodont described in 2018. It was the second genus of radiodont found to possess gnathobase-like structures and an atypical oral cone after Amplectobelua. The type species, Ramskoeldia platyacantha, was discovered in the Chengjiang biota of China, the home of numerous radiodontids such as Amplectobelua and Lyrarapax.

<i>Ursulinacaris</i> Extinct genus of hurdiid radiodonts

Ursulinacaris is a genus of hurdiid radiodont from the Cambrian of North America. It contains one known species, Ursulinacaris grallae. It was described in 2019, based on fossils of the frontal appendages discovered in the 1990s and thereafter. The endites of Ursulinacaris were very slender, unlike other hurdiids such as Peytoia or Hurdia. It was initially reported as the first hurdiid with paired endites, but Moysiuk & Caron (2021) suggested that it is actually the preservation of the fossils and thus no paired endites.

<i>Cambroraster</i> Extinct genus of radiodonts

Cambroraster is an extinct monotypic genus of hurdiid radiodont, dating to the middle Cambrian, and represented by the single formally described species Cambroraster falcatus. Hundreds of specimens were found in the Burgess Shale, and described in 2019. A large animal at up to 30 centimetres (12 in), it is characterized by a significantly enlarged horseshoe-shaped dorsal carapace (H-element), and presumably fed by sifting through the sediment with its well-developed tooth plates and short frontal appendages with hooked spines. Nicknamed the "spaceship" fossil when first found, for the way its dorsal carapace resembles the fictional Millennium Falcon, the specific epithet falcatus in its scientific name is a nod to that resemblance.

<i>Houcaris</i> Genus of radiodonts

Houcaris is a possibly paraphyletic radiodont genus, tentatively assigned to either Amplectobeluidae, Anomalocarididae or Tamisiocarididae, known from Cambrian Series 2 of China and the United States. The type species is Houcaris saron which was originally described as a species of the related genus Anomalocaris. Other possible species include H. magnabasis and H. consimilis. The genus Houcaris was established for the two species in 2021 and honors Hou Xianguang, who had discovered and named the type species Anomalocaris saron in 1995 along with his colleagues Jan Bergström and Per E. Ahlberg.

<i>Titanokorys</i> Extinct genus of giant hurdiid radiodont

Titanokorys is a genus of extinct hurdiid (peytoiid) radiodont that existed during the mid Cambrian. It is the largest member of its family from the Cambrian, with a body length of 50 cm (20 in) long, making it one of the largest animals of the time. It bears a resemblance to the related genus Cambroraster. Fossils of T. gainesi were first found within Marble Canyon in 2018. The fossils were not named until 2021 because they were assumed to be giant specimens of Cambroraster.

<i>Laminacaris</i> Genus of extinct arthropods

Laminacaris is a genus of extinct stem-group arthropods (Radiodonta) that lived during the Cambrian period. It is monotypic with a single species Laminacaris chimera, the fossil of which was described from the Chengjiang biota of China in 2018. Around the same time, two specimens that were similar or of the same species were discovered at the Kinzers Formation in Pennsylvania, USA. The first specimens from China were three frontal appendages, without the other body parts.

<i>Pahvantia</i> Extinct genus of radiodonts

Pahvantia is an extinct genus of hurdiid radiodont from the Cambrian. It is known by a single species, Pahvantia hastata, described from Wheeler Shale and Marjum Formation in Utah. Although it was once considered as filter feeder using large number of putative setae, this structures are later considered as misidentification of trunk materials.

<i>Cordaticaris</i> Genus of extinct stem-group arthropods

Cordaticaris is a genus of extinct hurdiid (peytoiid) radiodont that lived in what is now northern China during the middle Cambrian period. This animal was described in 2020 based on remains found in the Zhangxia Formation, located in the Shandong Province. It is differentiated from other members of its family by its unique heart-shaped frontal sclerite, and its frontal appendages bearing nine endites and seven more elongated subequal endites. This animal was important as it was the first Miaolingian aged hurdiid known from rock layers outside of laurentia, allowing paleontologists to get a better grasp of this families geographic range in life.

<i>Buccaspinea</i> Extinct genus of radiodont

Buccaspinea is an extinct genus of Cambrian hurdiid radiodont from the Marjum Formation, known from frontal appendages and a nearly complete albeit headless specimen with a preserved oral cone. Buccaspinea was described in January 2021, being the second-most recent hurdiid genus to be described.

References

  1. ↑ Lerosey-Aubril, Rudy; Pates, Stephen (2018-09-14). "New suspension-feeding radiodont suggests evolution of microplanktivory in Cambrian macronekton". Nature Communications. 9 (1): 3774. Bibcode:2018NatCo...9.3774L. doi: 10.1038/s41467-018-06229-7 . ISSN   2041-1723. PMC   6138677 . PMID   30218075. Dryad Data
  2. 1 2 Daley, Allison C.; Budd, Graham E.; Caron, Jean-Bernard (October 2013). "Morphology and systematics of the anomalocaridid arthropod Hurdia from the Middle Cambrian of British Columbia and Utah" . Journal of Systematic Palaeontology. 11 (7): 743–787. doi:10.1080/14772019.2012.732723. ISSN   1477-2019. S2CID   86465719.
  3. 1 2 3 Daley, A. C.; Budd, G. E.; Caron, J. B.; Edgecombe, G. D.; Collins, D. (2009). "The Burgess Shale anomalocaridid Hurdia and its significance for early euarthropod evolution". Science. 323 (5921): 1597–1600. Bibcode:2009Sci...323.1597D. doi:10.1126/science.1169514. PMID   19299617. S2CID   206517995.
  4. ↑ 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. 522 (7554): 77–80. Bibcode:2015Natur.522...77V. doi:10.1038/nature14256. ISSN   1476-4687. PMID   25762145. S2CID   205242881.
  5. ↑ 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. 288 (1955): 20211176. doi:10.1098/rspb.2021.1176. ISSN   0962-8452. PMC   8292756 . PMID   34284622.
  6. 1 2 Pates, Stephen; Daley, Allison C.; Lieberman, Bruce S. (2018). "Hurdiid radiodontans from the middle Cambrian (Series 3) of Utah". Journal of Paleontology. 92 (1): 99–113. doi:10.1017/jpa.2017.11. ISSN   0022-3360.
  7. ↑ Pates, Stephen; Daley, Allison C.; Edgecombe, Gregory D.; Cong, Peiyun; Lieberman, Bruce S. (2021). Zhang, Xi‐Guang (ed.). "Systematics, preservation and biogeography of radiodonts from the southern Great Basin, USA , during the upper Dyeran (Cambrian Series 2, Stage 4)". Papers in Palaeontology. 7 (1): 235–262. doi:10.1002/spp2.1277. ISSN   2056-2799.
  8. ↑ Sun, Zhixin; Zeng, Han; Zhao, Fangchen (2020-11-15). "A new middle Cambrian radiodont from North China: Implications for morphological disparity and spatial distribution of hurdiids". Palaeogeography, Palaeoclimatology, Palaeoecology. 558: 109947. doi:10.1016/j.palaeo.2020.109947. ISSN   0031-0182.
  9. 1 2 Walcott, Charles D. (1912-03-13). "Middle Cambrian Branchiopoda, Malacostraca, Trilobita, and Merostomata". Smithsonian Miscellaneous Collections. 57 (6).
  10. 1 2 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. 11 (7): 743–787. doi:10.1080/14772019.2012.732723. S2CID   86465719.
  11. ↑ Collins, Desmond (1996). "The "Evolution" of Anomalocaris and Its Classification in the Arthropod Class Dinocarida (nov.) and Order Radiodonta (nov.)". Journal of Paleontology. 70 (2): 280–293. Bibcode:1996JPal...70..280C. doi:10.1017/S0022336000023362. JSTOR   1306391. S2CID   131622496.
  12. ↑ D. Collins, in North American Paleontological Convention, Chicago, Abstracts with Programs, S. Lidgard, P. R. Crane, Eds. (The Paleontological Society, Special Publication 6, Chicago, IL, 1992), p. 66, 11.
  13. ↑ D. Collins (1999). "Dinocarids: the first monster predators on earth". Rotunda. Vol. 32. Royal Ontario Museum. p. 25.
  14. ↑ Fossil fragments reveal 500-million-year-old monster predator.
  15. ↑ New animal discovered by Canadian researcher.
  16. ↑ Scientists identify T-Rex of the sea
  17. ↑ Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. Bibcode:2006Palai..21..451C. doi:10.2110/palo.2003.P05-070R. JSTOR   20173022. S2CID   53646959.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.