Metriorhynchidae

Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period of Europe, North America and South America. The name Metriorhynchidae was coined by the Austrian zoologist Leopold Fitzinger in 1843. The group contains two subfamilies, the Metriorhynchinae and the Geosaurinae. They represent the most marine adapted of all archosaurs.

Description

Metriorhynchids are fully aquatic crocodyliforms. Their forelimbs were small and paddle-like, and unlike living crocodylians, they lost their osteoderms. Their body shape maximised hydrodynamy, as they did have a shark-like tail fluke. Like ichthyosaurs and plesiosaurs, metriorhynchids developed smooth, scaleless skin. However, unlike those marine reptiles, they were poikilothermic with little to no endothermic ability.
Metriorhynchids were the only group of archosaurs to become fully adapted to the marine realm, becoming pelagic in lifestyle. With tail flukes, reduced limb musculature, and long bones histologically comparable to other obligately aquatic animals, they were almost certainly incapable of terrestrial locomotion; combined with an unusually tall hip opening, as also seen in other obligately aquatic reptiles including the viviparous Keichousaurus, these characters suggest that metriorhynchids gave live birth. A fossil of a pregnant Dakosaurus female recovered from the Late Jurassic plattenkalk, Bavaria, preserves the complete skeleton of a neonate with small, paddle-like forelimbs unsuited for walking on land, similar to those of adults, further supporting live birth in metriorhynchids. Recent research posits that despite their successful adaptation to a pelagic lifestyle, basal metriorhynchids were uniquely disadvantaged among aquatic tetrapods in evolving into sustained swimmers due to little to no posterodorsal retraction of the external nares. The family has a wide geographic distribution, with material found in Argentina, Chile, Cuba, England, France, Germany, Italy, Mexico, Poland, Russia, Switzerland and Czech Republic.

Classification

analyses published during the 2000s cast doubt on the idea that many traditional metriorhynchid genera formed natural groups. The traditional species of Geosaurus, Dakosaurus and Cricosaurus were found to represent unnatural groups, and the species traditionally classified in these genera were reshuffled in a study published in November 2009 by Mark T. Young and Marco Brandalise de Andrade. The monophyly of Metriorhynchus and Teleidosaurus is also unsupported, and the species of these genera are pending reclassification.
The classification presented by Young and Andrade in 2009 was approved in later studies of the Metriorhynchidae. Metriorhynchidae is a node-based taxon defined in the PhyloCode by Mark T. Young and colleagues in 2024 as "the smallest clade within Metriorhynchoidea containing Thalattosuchus superciliosus, Gracilineustes leedsi, Metriorhynchus brevirostris, Rhacheosaurus gracilis, and Geosaurus giganteus" The cladogram below follows the topology from the 2020 analyses by Young et al. and reduced to genera only.

List of genera

The type genus of the family Metriorhynchidae is Metriorhynchus from the Middle to Late Jurassic. Other genera included within this family are Cricosaurus, Geosaurus, and Dakosaurus. Though once considered a metriorhynchid, Teleidosaurus has since been found to be slightly more distantly related to these animals within the superfamily Metriorhynchoidea.
Within this family, the genus Neustosaurus and Enaliosuchus are considered nomen dubium.
The genus Capelliniosuchus was once thought to be a metriorhynchid similar to Dakosaurus. However, it was later found to be a mosasaur.

Genus	Status	Author	Age	Location	Description	Synonyms	Images
Aggiosaurus		Ambayrac, 1913	late Oxfordian	France.	Sometimes considered to be a nomen dubium.		Image:Geosaurus [BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Cricosaurus	Valid	Wagner, 1858	middle Oxfordian to upper Valanginian	Argentina, Chile, Cuba, England, France, Germany, Mexico, Russia and Switzerland.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Dakosaurus	Valid	von Quenstedt, 1856	upper Kimmeridgian to lower Berriasian	Argentina, England, France, Germany, Mexico, Poland, Switzerland and possibly Russia.		Dacosaurus	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Enaliosuchus	nomen dubium	Koken, 1883	Valanginian	Germany.		-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Geosaurus	Valid	Cuvier, 1824	upper Kimmeridgian to upper Valanginian	France, Germany, Italy and Switzerland.		Brachytaenius Halilimnosaurus	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Gracilineustes	Valid	Young et al., 2010	middle Callovian to lower Kimmeridgian	England and France.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Maledictosuchus	Valid	Parrilla-Bel et al., 2013	middle Callovian to Kimmeridgian	Spain and Mexico.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Metriorhynchus	Valid	von Meyer, 1832	lower Kimmeridgian.	France.		Metiorychus	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Neptunidraco	Valid	Cau & Fanti, 2011	earliest Bathonian	Italy.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Neustosaurus	nomen dubium		Valanginian		— potential senior synonym of Enaliosuchus		[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Plesiosuchus	Valid	Owen, 1884	late Kimmeridgian to early Tithonian	England and possibly Spain.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Purranisaurus	Valid	Rusconi, 1948	upper Tithonian	Argentina and Chile.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Rhacheosaurus	Valid	von Meyer, 1831	lower Tithonian	Germany.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Suchodus	Valid	Lydekker, 1890	middle Callovian to lower Oxfordian	England and France.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Thalattosuchus	Valid	Young et al., 2020	lower Callovian to lower Oxfordian	England and France.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Torvoneustes	Valid	Andrade et al., 2010	Kimmeridgian to Tithonian	England.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
Tyrannoneustes	Valid	Young et al., 2013	Callovian	England.			[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]
-	-	-	-	-	-	-	[Image:Geosaurus BW.jpg\|thumb\|center\|150px\|Cricosaurus suevicus] [Image:Dakosaurus BW.jpg\|thumb\|center\|150px\|Dakosaurus andiniensis] [Image:Metriorhynchus superciliosum.jpg\|thumb\|center\|150px\|Thalattosuchus superciliosus] [Image:Neptunidraco NT.jpg\|thumb\|center\|150px\|Neptunidraco ammoniticus] [Image:Suchodus BW.jpg\|thumb\|center\|150px\|'Metriorhynchus' casamiquelai] [Image:Suchodus durobrivense.jpg\|thumb\|center\|150px\|Suchodus durobrivensis]

Subclades

Summary of the phylogenetic definitions of metriorhynchid subclades shown in the classification section. These are based on Young and colleagues 2024.

Name	Named by	Definition
Dakosaurina	Young et al., 2024	The largest clade within Metriorhynchidae containing Dakosaurus maximus, but not Metriorhynchus brevirostris, Geosaurus giganteus, Plesiosuchus manselii, and Torvoneustes carpenteri.
Geosaurina	Bonaparte, 1845	The largest clade within Metriorhynchidae containing Geosaurus giganteus, but not Metriorhynchus brevirostris, Plesiosuchus manselii, Torvoneustes carpenteri, and Dakosaurus maximus.
Geosaurinae	Bonaparte, 1845	The largest clade within Metriorhynchidae containing Geosaurus giganteus, but not Rhacheosaurus gracilis, Metriorhynchus brevirostris, and Gracilineustes leedsi.
Geosaurini	Bonaparte, 1845	The smallest clade within Metriorhynchidae containing Tyrannoneustes lythrodectikos, Geosaurus giganteus, Torvoneustes carpenteri, and Dakosaurus maximus.
Metriorhynchidae	Fitzinger, 1843	The smallest clade within Metriorhynchoidea containing Thalattosuchus superciliosus, Gracilineustes leedsi, Metriorhynchus brevirostris, Rhacheosaurus gracilis, and Geosaurus giganteus.
Metriorhynchinae	Lydekker, 1888	The smallest clade within Metriorhynchidae containing Rhacheosaurus gracilis, Metriorhynchus brevirostris, and Gracilineustes leedsi.
Plesiosuchina	Young et al.,2014	The largest clade within Metriorhynchidae containing Plesiosuchus manselii, but not Metriorhynchus brevirostris, Geosaurus giganteus, Torvoneustes carpenteri, and Dakosaurus maximus.
Rhacheosaurini	Young et al., 2011	The largest clade within Metriorhynchidae containing Rhacheosaurus gracilis, but not Metriorhynchus brevirostris and Gracilineustes leedsi.