What is Gryphaea?
{{italictitle}} {{DISPLAYTITLE:''Gryphaea''}} {{Automatic taxobox | fossil_range = {{fossil range|199.600|33.900}} [[Carnian]] - [[Eocene]] | image = Gryphaea arcuata fossil oyster (Blue Lias, Lower Jurassic; coastal cliffs near Lyme Regis, far-western Dorset County, southwestern England) 1 (15206675956).jpg | image_caption = ''Gryphaea arcuata'' from the [[Jurassic]] of [[England]] | taxon = Gryphaea | authority = Lamarck, 1801 }} '''''Gryphaea''''' (the '''Devil's toenail''') is a [[genus]] of [[extinct]] [[oyster]]s which were once very common. Their fossils are common on the [[Jurassic Coast]] in southern England, and in the margins of the old [[Sundance Sea]] in the United States. It is a [[Marine biology|marine]] [[bivalve]] [[mollusc]] in the [[family (biology)|family]] [[Gryphaeidae]]. These bivalves were at their peak in the [[Jurassic]] and [[Cretaceous]] periods, when they sat in huge [[mud]]dy oyster beds in shallow tropical seas. The [[genus]] survived a long time, but went extinct about 34 million years ago (mya). The oyster shell has two 'valves': a larger gnarly-shaped shell (the 'toenail') and a smaller, flattened shell, the 'lid'.<ref>Natural History Museum Picture Library. [http://piclib.nhm.ac.uk/results.asp?search=1&screenwidth=845&pixperpage=40&searchtxtkeys=gryphaea&lastsearchtxtkeys=&withinresults=&lstformats=&lstorients=All+Orientations&chkpho=&chkill=&chkpor=&chkarc=&chkfos=&chkspe=&chksem=&chkmodrel=]{{Dead link|date=January 2021 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The soft parts of the animal lived in the gap between the two shells, just like modern oysters. The shells have prominent growth bands. The large curved shell sat in the mud on the sea floor. == Where to find it == In England at the coasts of [[Redcar]] and [[Weymouth]] in the [[Kimmeridgian clay]]; in the U.S.A in riverbanks and cliffs of [[Texas]] and [[Kansas]]. They are often washed out of the clay onto the [[beach]] or river banksides. == References == {{reflist}} [[Category:Bivalves]]