{{Short description|Extinct genus of reptiles}} {{for|the ornithopod dinosaur|Dryosaurus}} {{Automatic taxobox | fossil_range = early Eocene (Ypresian), {{Fossil range|56|47}} | image = Dyrosaurus mount (retouched in the background).jpg | image_caption = Restored skeleton | image2 = Dyrosaurus maghribensis skeletal no osteoderms.png | image2_caption = Skeletal reconstruction of ''Dyrosaurus maghribensis'' in lateral view (bottom) and key elements in dorsal view (top) | image_upright = 1.1 | taxon = Dyrosaurus | authority = Pomel, 1894 | subdivision_ranks = Species | subdivision = * {{extinct}}''D. phosphaticus'' <small>(Thomas, 1893) (type)</small> * {{extinct}}''D. maghribensis'' <small>Jouve ''et al.'', 2006</small> }}
'''''Dyrosaurus''''' is a genus of extinct crocodylomorph that lived during the Early Eocene.<ref name="jouvepalaeo">{{cite journal |last1=Jouve |first1=Stéphane |last2=Iarochène |first2=Mohamed |last3=Bouya |first3=Baâdi |last4=Amaghzaz |first4=Mbarek |name-list-style=amp |title=A new dyrosaurid crocodyliform from the Palaeocene of Morocco and a phylogenetic analysis of Dyrosauridae |journal=Acta Palaeontologica Polonica |date=2005 |volume=50 |issue=3 |pages=581–594 |url=https://www.app.pan.pl/article/item/app50-581.html }}</ref> The name ''Dyrosaurus'' comes from {{lang|grc-Latn|sauros}} ({{lang|grc|σαῦρος}}) the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain) close to where the type species was discovered.<ref name="jouvemorocco">{{cite journal |last1=Jouve |first1=Stéphane |last2=Iarochène |first2=Mohamed |last3=Bouya |first3=Baâdi |last4=Amaghzaz |first4=Mbarek |name-list-style=amp |title=A new species of ''Dyrosaurus'' (Crocodylomorpha, Dyrosauridae) from the early Eocene of Morocco: phylogenetic implications |journal=Zoological Journal of the Linnean Society |date=2006 |volume=148 |issue=4 |pages=603–656 |doi=10.1111/j.1096-3642.2006.00241.x|doi-access=free }}</ref> It was a large reptile with an estimated body length of {{convert|6.5|m|ft}}.<ref>{{cite journal|author=Houssaye, A.|year=2013|title=Bone histology of aquatic reptiles: what does it tell us about secondary adaptation to an aquatic life?|journal=Biological Journal of the Linnean Society|volume=108|issue=1|pages=3–21|doi=10.1111/j.1095-8312.2012.02002.x|doi-access=free}}</ref>
== Species == left|thumb|Skull diagram of ''Dyrosaurus maghribensis'' Although the family Dyrosauridae is quite diverse and contains a variety of species, the genus ''Dyrosaurus'' has only two described species: ''D. phosphaticus'' and ''D. maghribensis''. ''D. phosphaticus'' was first discovered in Algeria and Tunisia whereas ''D. maghribensis'' has only been found in Morocco.<ref name="jouvemorocco"/> ''D. maghribensis'' differs from ''D. phosphaticus'' by several synapomorphies, most notably: a smooth dorsal margin of the parietal and widely opened choanae, interfenestral bar wide and strongly T-shaped instead of moderately T-shaped. In ''D. maghribensis'' the lateral and medial dorsal osteoderms are not sutured and have no serrated margin. The anterolateral margin of medial row of the dorsal osteoderms have a rounded lateral lobe and the lateral row of dorsal osteoderms are square in shape with rounded corners. In ''D. phosphaticus'' there are four longitudinal rows of square osteoderms that are thin and have shallow and wide pits. The osteoderms are square and the anterolateral margin of the medial dorsal osteoderms have an acute rounded process directed laterally.<ref name="jouvemorocco"/>
== History of discovery == thumb|Restoration of the animal thumb|Jaw and other fragments French paleontologist Auguste Pomel named the genus ''Dyrosaurus'' in 1894 for Djebel Dyr, a mountain near Tebessa in Algeria where its fossilised vertebrae were found in a phosphate mine. The holotype named MNHN 1901-11 includes one tooth, one caudal vertebra, one distal extremity of an ulna and one distal extremity of a radius. The first remains of ''Dyrosaurus'' were named ''Crocodilus phosphaticus'' by Thomas (1893) for Early Eocene crocodyliform remains from Gafsa, Tunisia. Pomel eventually synonymized the type species ''D. thevestensis'' with ''C. phosphaticus'' to form the new combination ''D. phosphaticus'', making ''phosphaticus'' the epithet of the ''Dyrosaurus'' type species.<ref name="jouvephosphat">{{cite journal |last1=Jouve |first1=Stéphane |title=A new description of the skull of ''Dyrosaurus phosphaticus'' (Thomas, 1893) (Mesoeucrocodylia: Dyrosauridae) from the Lower Eocene of North Africa |journal=Canadian Journal of Earth Sciences |date=1 March 2005 |volume=42 |issue=3 |pages=323–337 |doi=10.1139/e05-008|bibcode=2005CaJES..42..323J }}</ref><ref>{{cite journal |last=Pomel |first=A. |year=1894 |title=Découverte de champsosauriens dans les gisements de phosphorite du suessonien de l'Algérie |journal=Comptes rendus de l'Académie des Sciences |volume=118 |pages=1309–1310 |url=https://gallica.bnf.fr/ark:/12148/bpt6k3074r/f1309 }}</ref><ref>Buffetaut E. 1985. L'évolution des crocodiliens. Les animaux disparus-Pour la science, Paris, p. 109</ref> In 1903, the family Dyrosauridae was named by Giuseppe de Stefano referring to the locality for the holotype was found in Djebel Dyr, Algeria.<ref name="khosla">{{cite journal |last1=Khosla |first1=Ashu |last2=Sertich |first2=Joseph J. W. |last3=Prasad |first3=Guntupalli V. R. |last4=Verma |first4=Omkar |name-list-style=amp |title=Dyrosaurid remains from the Intertrappean beds of India and the Late Cretaceous distribution of Dyrosauridae |journal=Journal of Vertebrate Paleontology |date=2009 |volume=29 |issue=4 |pages=1321–1326 |doi=10.1671/039.029.0416 |jstor=20627142 |s2cid=130987967 }}</ref> Thévenin (1911a, 1911b), with some better preserved material, recognized that ''Dyrosaurus phosphaticus'' was a Lower Eocene crocodyliform. Many dyrosaurid remains are known, but they are often poorly preserved, which makes it difficult for paleontologists to get a strong understanding of the family.<ref name="jouvepalaeo"/>
== Palaeobiology ==
=== Thermoregulation === Stable isotopic and palaeohistological analysis indicates that ''Dyrosaurus'' was ectothermic, having similar body temperature, metabolic rate, bone tissue morphology, and red blood cell dimensions to present-day crocodylians, consistent with the hypothesis that neosuchians were ancestrally ectothermic. It likely thus shared a similar lifestyle to modern crocodylomorphs.<ref>{{Cite journal |last1=Faure-Brac |first1=Mathieu G. |last2=Amiot |first2=Romain |last3=de Muizon |first3=Christian |last4=Cubo |first4=Jorge |last5=Lécuyer |first5=Christophe |date=May 2022 |title=Combined paleohistological and isotopic inferences of thermometabolism in extinct Neosuchia, using Goniopholis and Dyrosaurus (Pseudosuchia: Crocodylomorpha) as case studies |url=https://www.cambridge.org/core/journals/paleobiology/article/combined-paleohistological-and-isotopic-inferences-of-thermometabolism-in-extinct-neosuchia-using-goniopholis-and-dyrosaurus-pseudosuchia-crocodylomorpha-as-case-studies/63D752466FE8A779498D465DF05739B3 |journal=Paleobiology |language=en |volume=48 |issue=2 |pages=302–323 |doi=10.1017/pab.2021.34 |issn=0094-8373 |access-date=23 November 2025 |via=Cambridge Core}}</ref>
==References== {{Reflist}}
{{Neosuchia|N.}} {{Taxonbar|from=Q136439}}
Category:Dyrosauridae Category:Prehistoric pseudosuchian genera Category:Prehistoric marine crocodylomorphs Category:Eocene crocodylomorphs Category:Eocene animals of Africa Category:Taxa named by Auguste Pomel Category:Fossil taxa described in 1894