Geosaurinae

Geosaurinae is a subfamily of metriorhynchid crocodyliforms from the Middle Jurassic to the Early Cretaceous (Bathonian - Aptian) of Europe, North America and South America.[1][2][3] Named by Richard Lydekker, in 1889, it contains the metriorhynchids Suchodus, Purranisaurus, Neptunidraco, Tyrannoneustes, Torvoneustes, Dakosaurus, Geosaurus and Plesiosuchus. The last four taxa form a tribe within Geosaurinae, the Geosaurini. Geosaurinae is one of two subfamilies of Metriorhynchidae, the other being Metriorhynchinae.[4]

Geosaurines Temporal range: Bathonian–Aptian PreꞒ Ꞓ O S D C P T J K Pg N
Dakosaurus maximus skull, Staatliches Museum für Naturkunde Stuttgart
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Suborder:	†Thalattosuchia
Family:	†Metriorhynchidae
Subfamily:	†Geosaurinae Lydekker, 1889
Genera
†Neptunidraco †Purranisaurus "Subclade T" †Torvoneustes †Tyrannoneustes †Geosaurini †Aggiosaurus †"Dakosaurina" †Dakosaurus †Geosaurina †Geosaurus †Ieldraan †Plesiosuchina †Plesiosuchus †Suchodus

Phylogeny

Life reconstructions showing the maximum body lengths for the four Geosaurini genera present in the late Kimmeridgian-early Tithonian of Western Europe

Geosaurinae is a stem-based taxon defined in 2009 as the most inclusive clade consisting of Geosaurus giganteus, but not Metriorhynchus geoffroyii.[1] Geosaurini was named by Lydekker in 1889, and it is a node-based taxon defined by Andrea Cau and Federico Fanti in 2011 as the least inclusive clade consisting of Geosaurus giganteus, Dakosaurus maximus and Torvoneustes carpenteri. The cladogram below follows the topology from a 2020 analysis by Young et al.[5]

Geosaurinae

"Metriorhynchus" casamiquelai     "Metriorhynchus" westermanni         Neptunidraco ammoniticus     "Metriorhynchus" brachyrhynchus      Geosaurini      Tyrannoneustes lythrodectikos       Torvoneustes spp.     'E-clade'     Purranisaurus potens               Ieldraan melkshamensis       Geosaurus lapparenti       Geosaurus giganteus     Geosaurus grandis               Plesiosuchus manselii     Suchodus durobrivensis         Dakosaurus andiniensis     Dakosaurus maximus

References

1. Mark T. Young and Marco Brandalise de Andrade (2009). "What is Geosaurus? Redescription of Geosaurus giganteus (Thalattosuchia: Metriorhynchidae) from the Upper Jurassic of Bayern, Germany". Zoological Journal of the Linnean Society. 157 (3): 551–585. doi:10.1111/j.1096-3642.2009.00536.x.CS1 maint: uses authors parameter (link)
2. Mark T. Young, Stephen L. Brusatte, Marcello Ruta and Marco Brandalise de Andrade (2010). "The evolution of Metriorhynchoidea (Mesoeucrocodylia, Thalattosuchia): an integrated approach using geometrics morphometrics, analysis of disparity and biomechanics". Zoological Journal of the Linnean Society. 158 (4): 801–859. doi:10.1111/j.1096-3642.2009.00571.x.CS1 maint: uses authors parameter (link)
3. Chiarenza AA, Foffa D, Young MT, Insacco G, Cau A, Carnevale G, Catanzariti R (2015). "The youngest record of metriorhynchid crocodylomorphs, with implications for the extinction of Thalattosuchia". Cretaceous Research. 56: 608–616. doi:10.1016/j.cretres.2015.07.001.CS1 maint: uses authors parameter (link)
4. Andrea Cau; Federico Fanti (2011). "The oldest known metriorhynchid crocodylian from the Middle Jurassic of North-eastern Italy: Neptunidraco ammoniticus gen. et sp. nov". Gondwana Research. 19 (2): 550–565. doi:10.1016/j.gr.2010.07.007.CS1 maint: uses authors parameter (link)
5. Young MT, Sachs S, Abel P, Foffa D, Herrera Y, Kitson JJN (2020). "Convergent evolution and possible constraint in the posterodorsal retraction of the external nares in pelagic crocodylomorphs". Zoological Journal of the Linnean Society. 189 (2): 494–520. doi:10.1093/zoolinnean/zlaa021.CS1 maint: uses authors parameter (link)