# Tommotiid > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Tommotiid > Markdown URL: https://mediated.wiki/source/Tommotiid.md > Source: https://en.wikipedia.org/wiki/Tommotiid > Source revision: 1354769310 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Extinct clade of lophophorates}} {{Automatic taxobox | name = Tommotiids | fossil_range = {{fossil range|Terreneuvian|Drumian|latest=Recent|ref={{Cite journal | url=http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A809326&dswid=-5399 |title = Discovery of the youngest known tommotiid from the middle Cambrian (Drumian) Nelson Limestone of Antarctica|journal = Diva|year = 2015|last1 = Skovsted|first1 = Christian|last2 = Bassett-Butt|first2 = Lewis}} }} (Tommotiida survives until present day through extant lophophorates) | image = Wufengella_reconstruction.jpg | image_caption = Interpretive drawing (top) and life restoration (bottom) of ''[Wufengella](/source/Wufengella)'' a [camenellan](/source/camenellan), and one of the few tommotiids known from articulated remains | image2 = Eccentrotheca.jpg | image2_caption = Life restoration of ''[Eccentrotheca](/source/Eccentrotheca)'', a sessile tommotiid | taxon = Tommotiida | authority = | subdivision_ranks = | subdivision = }} '''Tommotiids''' are an extinct group of [Cambrian](/source/Cambrian) invertebrates thought to be early [total-group](/source/Stem_group) [lophophorates](/source/Lophophorata) (the group containing [Bryozoa](/source/Bryozoa), [Brachiopoda](/source/Brachiopoda), and [Phoronid](/source/Phoronid)a), including members of the lophophorate [stem group](/source/stem_group), as well as early diverging members of the [crown group](/source/crown_group).{{cite journal | title= The Early Cambrian tommotiid ''Micrina'', a sessile bivalved stem group brachiopod | vauthors=Holmer LE, Skovsted CB, Brock GA, Valentine JL, Paterson JR | journal= Biology Letters|date=June 2008 | doi=10.1098/rsbl.2008.0277 |doi-access=free | pmid= 18577500 | volume= 4 | issue= 6 | pages= 724–728 | pmc= 2614141}}{{cite web|first=Christopher|last=Taylor|date=2008-06-27|title=Back to the Scleritome - Tommotiids Revealed!|work=Catalogue of Organisms|url=https://catalogue-of-organisms.blogspot.com/2008/06/back-to-scleritome-tommotiids-revealed.html|accessdate=2008-07-23}}{{cite journal | title=The scleritome of ''Eccentrotheca'' from the Lower Cambrian of South Australia: Lophophorate affinities and implications for tommotiid phylogeny | vauthors=Skovsted CB, Brock GA, Paterson JR, Holmer LE, Budd GE | journal=Geology |date=February 2008 | volume=36 | issue=2 | pages=171–174 | doi=10.1130/G24385A.1 | bibcode=2008Geo....36..171S}} The majority of tommotiids are mineralised with [calcium phosphate](/source/calcium_phosphate) rather than [calcium carbonate](/source/calcium_carbonate),{{Cite book |contribution = Early skeletal fossils |author = Bengtson, S. |editor = Lipps, J.H. |editor2 = Waggoner, B.M. |title = Neoproterozoic-Cambrian Biological Revolutions |year = 2004 |series = The Paleontological Society Papers |volume = 10 |pages = 67–78 |url = http://www.cosmonova.org/download/18.4e32c81078a8d9249800021554/Bengtson2004ESF.pdf |accessdate = 2008-07-18 |url-status = dead |archiveurl = https://web.archive.org/web/20081003122817/http://www.nrm.se/download/18.4e32c81078a8d9249800021554/Bengtson2004ESF.pdf|archivedate=2008-10-03 |doi = 10.1017/S1089332600002345}} although silicified examples hint that some species bore carbonate or carbonaceous [sclerite](/source/sclerite)s.{{Cite journal|vauthors=Skovsted CB|year=2016|title=A silicified tommotiid from the lower Cambrian of Greenland|journal=Bulletin of Geosciences|volume=91|issue=3|pages=553–559|issn=1214-1119|doi=10.3140/bull.geosci.1609|url=http://www.geology.cz/bulletin/fulltext/1609_Skovsted_161125.pdf|doi-access=free}} ''[Micrina](/source/Micrina)'' and ''[Paterimitra](/source/Paterimitra)'' possess bivalved shells in their larval phases, which preserve characters that might position them in the [Linguliformea](/source/Linguliformea) and [Rhynchonelliformea](/source/Rhynchonelliformea) stem lineages respectively. This would indicate that the brachiopod shell represents the retention of a larval character.{{Cite journal|vauthors=Holmer LE, Skovsted CB, Larsson C, Brock GA, Zhang Z|title=First record of a bivalved larval shell in Early Cambrian tommotiids and its phylogenetic significance|doi= 10.1111/j.1475-4983.2010.01030.x|journal=Palaeontology|volume=54|issue=2|pages=235–239|year=2011|doi-access=free|bibcode=2011Palgy..54..235H }} For a long part of their history, the tommotiids were only known from disarticulated shells - a complete organism had not been found. The 2008 discovery of ''[Eccentrotheca](/source/Eccentrotheca)'' offered the first insight into a complete organism, and permitted a reconstruction of the animal as a sessile, tube-like animal made up of a spiral of overlapping plates. Articulated specimens of ''[Paterimitra](/source/Paterimitra)'', discovered a year later, suggest a similar form and lifestyle - it is possible that many tommotiids need redescribing as sessile tube-dwellers.{{Cite journal|vauthors=Skovsted CB, Holmer LE, Larsson CM, Högström AE, Brock GA, Topper TP, Balthasar U, Stolk SP, Paterson JR|title=The scleritome of ''Paterimitra'': an Early Cambrian stem group brachiopod from South Australia|journal=Proceedings of the Royal Society B: Biological Sciences|volume=276|issue=1662|pages=1651–1656|date=May 2009|issn=0962-8452|pmid=19203919|pmc=2660981|doi= 10.1098/rspb.2008.1655}} ''Eccentrotheca'' and other similar sessile tommotiids were likely [filter feeder](/source/filter_feeder)s, similar to modern lophophorates. However, the discovery of the articulated [camenellan](/source/camenellan) ''[Wufengella](/source/Wufengella)'' showed that it was a free-living worm-like animal, suggesting that it was not a [crown-group](/source/Crown_group) lophophorate, as the last living common ancestor of all living lophophorates has been predicted to be [sessile](/source/Sessility_(motility)), as bryozoans, brachiopods and phoronids are. This indicates that tommotiids are [paraphyletic](/source/paraphyletic), with some tommotiids more closely related to bryozoans, brachiopods and phoronids than to other tommotiids.{{Cite journal |last1=Guo |first1=Jin |last2=Parry |first2=Luke A. |last3=Vinther |first3=Jakob |last4=Edgecombe |first4=Gregory D. |last5=Wei |first5=Fan |last6=Zhao |first6=Jun |last7=Zhao |first7=Yang |last8=Béthoux |first8=Olivier |last9=Lei |first9=Xiangtong |last10=Chen |first10=Ailin |last11=Hou |first11=Xianguang |last12=Chen |first12=Taimin |last13=Cong |first13=Peiyun |date=September 2022 |title=A Cambrian tommotiid preserving soft tissues reveals the metameric ancestry of lophophorates |journal=Current Biology |volume=32 |issue=21 |language=en |pages=4769–4778.e2 |doi=10.1016/j.cub.2022.09.011|s2cid=252564106 |doi-access=free |bibcode=2022CBio...32E4769G |hdl=1983/bede5ebd-85b8-4b09-b54e-a892489f33fb |hdl-access=free }} These discoveries have produced an alternative model for the origin of the [brachiopod](/source/brachiopod)s; it suggested that they evolved by the reduction of sessile tube-like organisms, until only two shells were left. This contrasts with the [brachiopod fold hypothesis](/source/brachiopod_fold_hypothesis) which suggests that they formed by the folding of a [halkieriid](/source/halkieriid)-like organism. == Taxonomy == left|thumb|Phylogenetic tree of early lophophorates Five families are recognized:{{cite journal|vauthors=Devaere L, Clausen S, Monceret É, Vizcaïno D, Vachard D, Genge M|date=2014|title=The tommotiid ''Kelanella'' and associated fauna from the early Cambrian of southern Montagne Noire (France): Implications for camenellan phylogeny|journal=Palaeontology|volume=57|issue=5|pages=979–1002|doi=10.1111/pala.12098|s2cid=129242398 |doi-access=free|bibcode=2014Palgy..57..979D }} {{Taxon list | [Tommotiidae](/source/Tommotiidae) | Missarzhevsky in Rozanov ''et al.'', 1969 | [Tannuolinidae](/source/Tannuolinidae) |Fonin and Smirnova, 1967 | [Sunnaginiidae](/source/Sunnaginiidae) |Landing, 1984 | [Kennardiidae](/source/Kennardiidae) |Laurie, 1986 | [Lapworthellidae](/source/Lapworthellidae) |Missarzhevsky in Rozanov and Missarzhevsky, 1966 }} {| |- ! Taxon ! Relationship{{Cite journal|vauthors=Skovsted CB, Brock GA, Topper TP, Paterson JR, Holmer LE|title=Scleritome construction, biofacies, biostratigraphy and systematics of the tommotiid ''Eccentrotheca helenia'' sp. nov. from the Early Cambrian of South Australia|journal=Palaeontology|volume=54|issue=2|pages=253–286|year=2011|doi= 10.1111/j.1475-4983.2010.01031.x|doi-access=|bibcode=2011Palgy..54..253S }} |- |''[Kulparina](/source/Kulparina)'' | Stem [paterinid](/source/Paterinata) |- | ''[Paterimitra](/source/Paterimitra)'' | Stem paterinid |- | ''[Askepasma](/source/Askepasma)'' | Stem (or crown?) paterinid |- | ''[Tannuolina](/source/Tannuolina)'' | Stem [linguliform](/source/Linguliformea) |- | ''[Micrina](/source/Micrina)'' | Stem Linguliform |- | ''[Mickwitzia](/source/Mickwitzia)'' | Stem (or crown?) linguliform |- | ''[Camenella](/source/Camenella)'' | Stem [brachiozoa](/source/brachiozoa)n |- | ''[Dailyatia](/source/Dailyatia)'' | Stem brachiozoan |- | ''[Lapworthella](/source/Lapworthella)'' | Stem brachiozoan |- | ''[Eccentrotheca](/source/Eccentrotheca)'' | Stem phoronid or brachiopod |- |''[Wufengella](/source/Wufengella)'' | Stem lophophorate |} ==References== {{Reflist|40em}} {{Taxonbar|from=Q7819141}} Category:Cambrian invertebrates Category:Lophophorata --- Adapted from the Wikipedia article [Tommotiid](https://en.wikipedia.org/wiki/Tommotiid) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Tommotiid?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.