# Holyoakia > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Holyoakia > Markdown URL: https://mediated.wiki/source/Holyoakia.md > Source: https://en.wikipedia.org/wiki/Holyoakia > Source revision: 1271598834 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Genus of trilobites}} {{Automatic taxobox | fossil_range = late [Botomian](/source/Botomian)
~{{fossil range|518|516}} | image = Holyoakia simpsoni.jpg | image_caption = ''Holyoakia simpsoni'', © Dave Simpson | taxon = Holyoakia | authority = Palmer ''in'' Palmer & Rowell, 1995 | subdivision_ranks = Species | subdivision = * ''Holyoakia granulosa'' Palmer ''in'' Palmer & Rowell, 1995 ([Type](/source/Type_(biology))) * ''Holyoakia simpsoni'' Paterson & Jago, 2006 }} '''''Holyoakia''''' is a genus of very small (up to 7½ mm long) [trilobite](/source/trilobite)s of the family [Dorypygidae](/source/Dorypygidae), from the late Lower [Cambrian](/source/Cambrian) (Late Botonian) of South Australia and Antarctica. == Etymology == ''Holyoakia simpsoni'' was named in honor of David Simpson from Adelaide, who collected the first specimens. == Distribution == * ''Holyoakia granulosa'' has only been collected from the late Lower Cambrian of Antarctica (presumably Botomian, [Shackleton Limestone](/source/Shackleton_Limestone), Central Transantarctic Mountains) * ''Holyoakia simpsoni'' only occurs in the late Lower Cambrian of South Australia (mid-late Botomian, [Emu Bay Shale](/source/Emu_Bay_Shale), Big Gully, Kangaroo Island). == Taxonomy == The genus was originally with reservation placed in the [Emuellidae](/source/Emuellidae). The genus however lacks the specific characteristics of this family, most notably, the clearly furrowed [glabella](/source/Trilobite) that is rounded at the frontal end, the hook-shaped eye ridges that run parallel to the margin of the head shield (or [cephalon](/source/Trilobite)), clearly distinguishable prothorax of six segments, the most backward one with much larger spines than all others, and opistothorax of many segments, while the pygidium is tiny. ''Holyoakia'' however, has a rectangular glabella, difficult to discern eye ridges, a thorax of eight segments which is not differentiated and has no macropleural segment, and the pygidium is not much smaller than the cephalon.{{cite journal|last1= Paterson|first1= R.J.|last2= Jago|first2=J.B.|year= 2006|title= New trilobites from the Lower Cambrian Emu Bay Shale Lagerstätte at Big Gully, Kangaroo Island, South Australia.|journal= Memoirs of the Association of Australasian Palaeontologists|volume= 32|pages= 43–57|hdl= 1959.14/10651|issn= 0810-8889}} == Ecology == ''Holyoakia simpsoni'' occurs together with ''[Redlichia takooensis](/source/Redlichia_takooensis)'', ''[Estaingia bilobata](/source/Estaingia_bilobata)'', ''[Balcoracania dailyi](/source/Balcoracania)'', and ''[Megapharanaspis nedini](/source/Megapharanaspis)''. == Key to the species == {| |- valign="top" align="left" ! scope="row" width="3%" | '''1''' |Pygidium subtriangular, about 1½× as wide as long. Pygidial axis with 8 discernible rings. 6 pairs of pygidial pleura terminate in well developed spines.
→ '''''Holyoakia granulosa''''' |- valign="top" align="left" ! scope="row" width="3%" | '''-''' |Pygidium transversely elliptical, more than 2× as wide as long. Pygidial axis with 5 discernible rings. 4 pairs of pygidial pleural furrows end in nodes.
→ '''''Holyoakia simpsoni''''' |} == References == {{Portal|Paleontology}} {{Reflist}} == Further reading == {{refbegin}} * {{cite book | chapter = Burgess Shale-type Localities: The global picture | author = Hagadorn, J.W. | editor = Bottjer, D.J. |editor2=W. Etter |editor3=J.W. Hagadorn |editor4=C.M. Tang | title=Exceptional Fossil Preservation -- A Unique View on the Evolution of Marine Life | publisher=Columbia University Press | year=2002 | isbn =0231102542 }} * {{cite web |author1=Greg Edgecombe |website=The Australian Museum | title=Australian Trilobites: A Species List and Bibliography | url=http://www.austmus.gov.au/palaeontology/research/trilobites03.htm? | accessdate=August 23, 2005 }} * {{cite web | author=Sam Gon III | title=A guide to the Orders of Trilobites | url=http://www.trilobites.info/index.htm | accessdate=August 23, 2005 }} * {{cite journal | author=Nedin, C. | title=The Emu Bay Shale, a Lower Cambrian fossil Lagerstätte, Kangaroo Island, South Australia | journal=Memoirs of the Association of Australasian Palaeontologists | year=1995 | volume=18 | pages=31–40 }} * {{cite web |author = Simpson, Dave |title = Trilobites of South Australia |url = http://info.esc.net.au/~dasimpson/index.htm |accessdate = August 23, 2005 |url-status = dead |archiveurl = https://web.archive.org/web/20060219192556/http://info.esc.net.au/~dasimpson/index.htm |archivedate = February 19, 2006 }} {{refend}} {{Taxonbar|from=Q5887050}} Category:Corynexochida genera Category:Dorypygidae Category:Cambrian trilobites Category:Trilobites of Antarctica Category:Trilobites of Australia Category:Fossil taxa described in 1995 --- Adapted from the Wikipedia article [Holyoakia](https://en.wikipedia.org/wiki/Holyoakia) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Holyoakia?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.