Chondrosteidae

{{Short description|Extinct family of fishes}}

{{Automatic taxobox

| fossil_range = {{fossilrange|199.3|174.1|Sinemurian to Toarcian{{cite book |author1=L. Grande |author2=W.E. Bemis |name-list-style=amp |editor1=M. L. J. Stiassny |editor2=L. R. Parenti |editor3=G. D. Johnson |title= Interrelationships of Fishes |chapter= Interrelationships of Acipenseriformes, with comments on "Chondrostei".|year=1996 |publisher=Academic Press, San Diego |pages=85–115}}}}

| image = Strongylosteus hindenburgi Tubingen.JPG

| image_caption = Skeleton of Strongylosteus hindenburgi

| image2 = Catalogue of the fossil fishes in the British Museum (Natural History) (1889) (20393616949).jpg

| image2_caption = Skeletal reconstruction of Chondrosteus

| parent_authority = Aldinger, 1937

| display_parents = 2

| taxon = Chondrosteidae

| authority = Egerton, 1858

| subdivision_ranks = Included genera

| subdivision = *{{extinct}}Chondrosteus{{cite book |last1=Agassiz |first1=Louis |title=Recherches sur les Poissons Fossiles, Tome I |year=1833–43 |publisher=Imprimerie de Petitpierre, Neuchâtel |pages=1–188}} Egerton, 1858 (ex Agassiz, 1834)

• {{extinct}}Gyrosteus{{cite book |last1=Agassiz |first1=Louis |title=Recherches sur les Poissons Fossiles, Tome I |year=1833–43 |publisher=Imprimerie de Petitpierre, Neuchâtel |pages=1–188}} Woodward, 1889 (ex Agassiz, 1834)
• {{extinct}}Strongylosteus Jaekel, 1931

}}

File:Chondrosteus acipenseroides - Lyme Regis.jpg from Lyme Regis]]

File:Chondrosteus hindenburgi 1.JPG fossil from Posidonia Shale, Staatliches Museum für Naturkunde Stuttgart]]

Chondrosteidae {{IPAc-en|ˌ|k|ɒ|n|d|r|oʊ-|s|t|i|ˈ|aɪ|d|iː}} is a family of extinct marine actinopterygian fishes, known from the Early Jurassic of Europe. They are closely related to modern sturgeons and paddlefish of the order Acipenseriformes, and are either placed as part of that order{{Cite journal |last1=Hornung |first1=Jahn J. |last2=Sachs |first2=Sven |date=2020-01-22 |title=First record of Gyrosteus mirabilis (Actinopterygii, Chondrosteidae) from the Toarcian (Lower Jurassic) of the Baltic region |journal=PeerJ |language=en |volume=8 |pages=e8400 |doi=10.7717/peerj.8400 |doi-access=free |pmid=32002331 |pmc=6982408 |issn=2167-8359}} or the separate order Chondrosteiformes within the Chondrostei.{{Cite book |last1=Nelson |first1=Joseph S. |url=http://dx.doi.org/10.1002/9781119174844 |title=Fishes of the World |last2=Grande |first2=Terry C. |last3=Wilson |first3=Mark V. H. |date=2016-02-22 |publisher=Wiley |doi=10.1002/9781119174844 |isbn=978-1-118-34233-6}} Three genera are known, Chondrosteus, Gyrosteus, and Strongylosteus.{{cite journal |last1=Bemis |first1=William E. |last2=Findeis |first2=Eric K. |last3=Grande |first3=Lance |title=An overview of Acipenseriformes |journal=Environmental Biology of Fishes |date=1997 |volume=48 |issue=1–4 |pages=25–71|doi=10.1023/A:1007370213924 |bibcode=1997EnvBF..48...25B |s2cid=24961905 }} Included species were of large size, with body lengths ranging from {{convert|2|m|ft}} up to {{convert|7|m|ft}}. Their skeleton was largely made up of bones (unlike living chondrosteans), but ossification was reduced compared to other ray-fins.{{cite journal |last1=Hilton |first1=Eric J. |last2=Forey |first2=Peter L. |title=Redescription of †Chondrosteus acipenseroides Egerton, 1858 (Acipenseriformes, †Chondrosteidae) from the lower Lias of Lyme Regis (Dorset, England), with comments on the early evolution of sturgeons and paddlefishes |journal=Journal of Systematic Palaeontology |date=2009 |volume=7 |issue=4 |pages=427–453 |doi= 10.1017/S1477201909002740|bibcode=2009JSPal...7..427H |s2cid=86821521 }}