Delgadella

{{Automatic taxobox | fossil_range = {{Geological range|522|520|Late Atdabanian to Botomian}} | image = Delgadella.png | image_upright = 0.6 | image_caption = A drawing of ''Delgadella lenaicus'', Lena River, Yakutia | taxon = Delgadella | authority = Walcott, 1908 | synonyms = ''Alemtejoia'', ''Delgadodiscus'', ''Delgadoia'', ''Pagetiellus'', ''Pentagonalia'' | subdivision_ranks = Species | subdivision = * ''D. lusitanica'' (Delgado, 1904) (type species) = ''Lingulepis lusitanica'' * ''D. caudatus'' (Delgado, 1904) = ''Delgadodiscus caudatus'', ''Microdiscus caudatus'' * ''D. lenaicus'' (Toll, 1899) = ''Microdiscus lenaicus'' }}

'''''Delgadella''''' is a diminutive agnostid that lived during the late Lower Cambrian (Atdabanian to Botomian, over 500 million years ago) and has been found in Russia (Siberian Platform, Altay Mountains), Mongolia, Spain, Italy (Sardinia), Portugal, Morocco and Canada (Newfoundland). It can be recognized by its strongly effaced headshield and tailshield, with narrow but distinct furrows and borders along its margins, and three thorax segments.<ref name="Treatise">{{cite book|editor= Whittington, H. B.|series= Treatise on Invertebrate Paleontology|title= Part O, Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida|year= 1997|display-editors=etal}}</ref>

== Description == The headshield (or cephalon) is convex, and axial furrow that surrounds the central area (or glabella) almost obsolete, particularly on the external surface. The glabella has no transverse furrows. The border furrow is distinct and wide anteriorly, and the border distinct and narrow. The eye lobe (or palpebral lobe) is poorly defined. The free cheeks (or librigenae) are long. The thorax has three segments. The tailshield (or pygidium) has a long axis of 10 almost indiscernible rings. The furrow that defines the axis in the pygidium (or rhachis) is almost obsolete. The area outside the rhachis (or pleural zone) is usually smooth, and like on the cephalon, the border and border furrow are very narrow but distinct.<ref name="Treatise"/>

== Distribution == * ''Delgadella'' occurs in the Lower Cambrian of the Russian Federation (Atdabanian, ''Judomia'' trilobite-zone, Tyuser Formation, Chekurovka village, Biskeebit River mouth near Lena River 71.0° N, 127.5° E,<ref>{{cite journal|author= A.Y. Rozanov |author2=V.V. Missarzhevsky |author3=N.A. Volkova |author4=L.G. Voronova |author5=I.N. Krylov |author6=B.M. Keller |author7=I.K. Korolyuk |author8=K. Lendzion |author9=R. Mikhnyar |author10=N.G. Pykhova |author11=A.D. Sidorov|year= 1969|title= Tommotskiu jarus i problema nizhney granisty kembriya|journal= Trudy Geoligske Institut Leningrad|volume= 206|pages= 1–379}} ''cited in'' {{cite web |website=Paleobiological Database |url=http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=56855 |title=Archived copy |access-date=2013-03-15 |archive-date=2013-04-12 |archive-url=https://archive.today/20130412083717/http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=56855 |url-status=dead }}</ref> Erkeket Formation, Mattaiya Creek, 71.5° N, 124.6° E,<ref>{{cite journal|author= I.V. Korovnikov|year= 2007|title= Trilobites of the Suborder Eodiscina from the Lower Cambrian of the Northeastern Siberian Platform (Khorbosuonka River Section)|journal= Paleontological Journal|volume= 41|issue= 6|pages= 614–620|doi=10.1134/s0031030107060044|bibcode= 2007PalJ...41..614K|s2cid= 128398586}} ''cited in'' {{cite web|website=Paleobiolobical Database |url=http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=96839 }}{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> '' Bergeroniellus gurarii'' trilobite-zone, Sinsk Formation, Algal Lens Yakutia, 61.1° N, 126.6°;<ref>{{cite journal|author= E.Y. Ivantsov|author2=A. Y. Zhuravlev |author3=A. V. Leguta |author4=V. A. Krassilov |author5=L. M. Melnikova |author6=G. T. Ushatinskaya |year= 2005|title= Palaeoecology of the Early Cambrian Sinsk biota from the Siberian Platform|journal= Palaeogeography, Palaeoclimatology, Palaeoecology|volume=220|issue=1–2 |pages= 69–88|doi=10.1016/j.palaeo.2004.01.022|bibcode=2005PPP...220...69I }} ''cited in'' {{cite journal|journal = Palaeogeography, Palaeoclimatology, Palaeoecology|volume = 220|issue = 1–2|pages = 69–88|url = http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=90438|doi = 10.1016/j.palaeo.2004.01.022|title = Palaeoecology of the Early Cambrian Sinsk biota from the Siberian Platform|year = 2005|last1 = Ivantsov|first1 = Andrey Yu.|last2 = Zhuravlev|first2 = Andrey Yu.|last3 = Leguta|first3 = Anton V.|last4 = Krassilov|first4 = Valentin A.|last5 = Melnikova|first5 = Lyudmila M.|last6 = Ushatinskaya|first6 = Galina T.|bibcode = 2005PPP...220...69I|url-access = subscription|archive-date = 2013-04-12|access-date = 2013-03-15|archive-url = https://archive.today/20130412085137/http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=90438|url-status = dead}}</ref> Botomian, ''Lapworthella bella'' small shelly-zone, Krasnoporog Formation, Sukharikha River, Krasnoyarskiy Kray, 67.2° N, 87.0° E),<ref>{{cite journal|author= S. M. Rowland|author2=V. A. Luchinina |author3=I. V. Korovnikov |author4=D. P. Sipin |author5=A. I. Tarletskov |author6=A. V. Fedoseev |year= 1998|title= Biostratigraphy of the Vendian-Cambrian Sukharikha River section, northwestern Siberian Platform|journal= Canadian Journal of Earth Sciences|volume= 35|issue= 4|pages= 339–352|doi=10.1139/cjes-35-4-339|bibcode=1998CaJES..35..339R }} ''cited in'' {{cite web|website=Paleobiological Database |url=http://museumu03.museumwww.naturkundemuseum-berlin.de/cgi-bin/bridge.pl?action=basicCollectionSearch&collection_no=80843 }}{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> and Spain (Atdabanian, upper part of the La Hoya member, Alconera Formation).<ref>{{cite book|editor= Eladio Liñán |title= The Cambrian system in Iberia|publisher= Instituto Geologico y Minero d’ Espagna|series= Guadernos del Museo Minero|number= 3|pages= 1–65}}</ref>

== References == {{Reflist}}

Category:Eodiscina Category:Cambrian trilobites Category:Fossils of Canada Category:Fossils of Italy Category:Fossils of Mongolia Category:Fossils of Morocco Category:Fossils of Russia Category:Fossils of Spain Category:Fossils of Portugal Category:Paleontology in Newfoundland and Labrador Category:Agnostida genera