Microcleidus

{{Short description|Extinct genus of reptiles}}

{{Automatic taxobox

| fossil_range = Toarcian
~{{fossilrange|182|175}}

| image = Microcleidus NHM.jpg

| image_caption = Fossil M. homalospondylus

| taxon = Microcleidus

| authority = Watson, 1909

| type_species = Plesiosaurus homalospondylus

| type_species_authority = (Owen, 1865)

| subdivision_ranks = Other species

| subdivision =

  • M. macropterus (Seeley, 1865)
  • M. tournemirensis (Sciau et al., 1990)
  • M. melusinae Vincent et al., 2019

| synonyms =

M. macropteus

  • Plesiosaurus macropteus Seeley, 1865
  • Eretmosaurus macropterus Benton and Spencer, 1995

M. tournemirensis

  • Plesiosaurus tournemirensis Sciau et al., 1990
  • Occitanosaurus tournemirensis
    Bardet et al., 1999

}}

Microcleidus is an extinct genus of sauropterygian reptile belonging to the Plesiosauroidea. The species has 40 neck vertebrae and a short tail of 28 vertebrae. Fossils of the genus have been found in France, the Posidonia Shale in Germany and Luxembourg, and the Alum Shale Formation of England.

Description

File:Microcleidus homalospondylus.png

The type species, M. homalospondylus, was the largest, measuring {{cvt|5.1|m|ft}} long and weighing {{cvt|650|kg|lbs}}. Other species were smaller: M. tournemirensis was about {{cvt|4|m|ft}} long and weighed {{cvt|300|kg|lbs}}, and M. melusinae was about {{cvt|3|m|ft}} long and weighed {{cvt|120|kg|lbs}}.{{Cite journal|author1=Valentin Fischer |author2=Nikolay G. Zverkov |author3=Maxim S. Arkhangelsky |author4=Ilya M. Stenshin |author5=Ivan V. Blagovetshensky |author6=Gleb N. Uspensky |year=2020 |title=A new elasmosaurid plesiosaurian from the Early Cretaceous of Russia marks an early attempt at neck elongation |journal=Zoological Journal of the Linnean Society |volume=192 |issue=4 |pages=1167–1194 |doi=10.1093/zoolinnean/zlaa103 |hdl=2268/251614 |url=https://orbi.uliege.be/handle/2268/251614 }}[https://orbi.uliege.be/bitstream/2268/251614/2/Supp_info.pdf Supplementary Information]{{cite book|last=Paul|first=Gregory S.|year=2022|title=The Princeton Field Guide to Mesozoic Sea Reptiles|pages=108–109|doi=10.1515/9780691241456|isbn=9780691193809|s2cid=251553177|publisher=Princeton University Press}}

Classification

File:'Microcleidus' macropterus.jpg]]

Species include: Microcleidus homalospondylus (Owen 1865) and Microcleidus macropterus (Seeley 1865).

Occitanosaurus tournemirensis (originally "Plesiosaurus" tournemirensis), was named by Sciau et al. in 1990, based on a nearly complete skeleton of an animal approximately 4 meters (13 ft) long.Ketchum HF, Benson RBJ. Global interrelationships of Plesiosaur (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses. Biological Reviews

It was later found to be a species of Microcleidus.

The following cladogram follows an analysis by Ketchum & Benson, 2011.{{cite journal |author1=Hilary F. Ketchum |author2=Roger B. J. Benson |year=2011 |title=A new pliosaurid (Sauropterygia, Plesiosauria) from the Oxford Clay Formation (Middle Jurassic, Callovian) of England: evidence for a gracile, longirostrine grade of Early-Middle Jurassic pliosaurids |journal=Special Papers in Palaeontology |volume=86 |pages=109–129 }}

{{clade| style=font-size:85%;line-height:85%

|label1=Pistosauria

|1={{clade

|1="Pistosaurus postcranium"

|2={{clade

|1=Augustasaurus hagdorni

|2=Bobosaurus forojuliensis

|3=Pistosaurus

|4=Yunguisaurus liae

|label5=Plesiosauria

|5={{clade

|label1=Pliosauroidea

|1={{clade

|label1=Pliosauridae

|1={{clade

|1=Thalassiodracon hawkinsii

|2={{clade

|1=Hauffiosaurus spp.

|2={{clade

|1=Attenborosaurus conybeari

|2=advanced pliosaurids }} }} }}

|label2=Rhomaleosauridae

|2={{clade

|1=NHMUK OR 49202 [now Anningasaura lymense]

|2={{clade

|1=advanced rhomaleosaurids

|2={{clade

|1="Plesiosaurus" macrocephalus

|2={{clade

|1=Archaeonectrus rostratus

|2=Macroplata tenuiceps }} }} }} }} }}

|label2=Plesiosauroidea

|2={{clade

|1=OUMNH J.10337 [now Stratesaurus taylori]

|2={{clade

|label1=Plesiosauridae

|1={{clade

|1=Seeleyosaurus guilelmiimperatoris

|2={{clade

|1=OUMNH J.28585

|2=Plesiosaurus dolichodeirus }} }}

|2={{clade

|1=Elasmosauridae and Cryptoclidia

|2={{clade

|1=Microcleidus homalospondylus

|2={{clade

|1=Hydrorion brachypterygius

|2=Occitanosaurus tournemiensis }} }} }} }} }} }} }} }} }}

See also

References

{{Reflist}}

= Bibliography =

  • Bardet, Nathalie; Fernandez, Marta; Garcia-Ramos, Jose Carlos; Superbiola, Xabier Pereda; Pinuela, Laura; Ruiz-Omenaca, Jose Ignacio; and Vincent, Peggy (2008). "[https://web.archive.org/web/20111004102618/http://www.dinoastur.com/wp-content/uploads/2008/04/bardet-et-al-2008.pdf A juvenile plesiosaur from the Pliensbackian (Lower Jurassic) of Asturias, Spain]". Journal of Vertebrate Paleontology 28(1): 258–263
  • [http://www.plesiosaur.com] Plesiosaur.com 13 Oct 2006
  • [http://www.palaeos.com/Vertebrates/Units/220Lepidosauromorpha]{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }} Palæos.com 13 Oct 2006
  • [https://www.cambridge.org/core/journals/geological-magazine/article/abs/microcleidus-melusinae-a-new-plesiosaurian-reptilia-plesiosauria-from-the-toarcian-of-luxembourg/EFF3920EB96A0E7930F1C4C51E4F238F]

{{Sauropterygia|Pliosauroidea}}

{{Taxonbar|from=Q2462673}}

Category:Plesiosauroids

Category:Early Jurassic plesiosaurs of Europe

Category:Toarcian genera

Category:Jurassic England

Category:Fossils of England

Category:Jurassic France

Category:Fossils of France

Category:Jurassic Germany

Category:Fossils of Germany

Category:Posidonia Shale

Category:Fossil taxa described in 1909

Category:Sauropterygian genera