''Tyrannoneustes'' is an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
geosaurine metriorhynchid
Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period (Bajocian to early Aptian) of Europe, North America and South America. The name Metriorhynchidae ...
crocodyliform
Crocodyliformes is a clade of Crurotarsi, crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the ...
from the
Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 165.3 ± 1.1 Ma (million years ago) and 161.5 ± 1.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...
stage
Oxford Clay Formation of England and the
Marnes de Dives of France. It contains a single species, ''Tyrannoneustes lythrodectikos'', meaning "blood-biting tyrant swimmer".
History and description

The genus was rediscovered after a century of storage in a museum basement after being unearthed by fossil hunter
Alfred Nicholson Leeds
Alfred Nicholson Leeds (9 March 184725 August 1917) was an English amateur palaeontologist.
Biography
Leeds was born at Eyebury, Peterborough, the youngest of the eight children of Edward Thurlow Leeds (180251) and Eliza Mary Leeds (née Nichols ...
between the years of 1907 and 1909. Its lower jaw measured about 26 inches long and its teeth were blade-like, likely built to attack prey as large or larger than itself, similar to the
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...
''
Dakosaurus
''Dakosaurus'' is an extinct genus of crocodylomorph within the family Metriorhynchidae that lived during the Late Jurassic and Early Cretaceous. It was large, with teeth that were serrated and compressed lateromedially (flattened from side to s ...
'', ''
Torvoneustes'', and ''
Plesiosuchus''.
The holotype specimen was estimated to be more than in total body length by Young and his colleagues.
[ Two other specimens (PETMG:R176 and NHMUK PV R3939) belonged to much larger individuals, measuring and in total body length, respectively.]
References
{{Taxonbar, from=Q2784897
Prehistoric pseudosuchian genera
Prehistoric marine crocodylomorphs
Callovian life
Middle Jurassic crocodylomorphs
Middle Jurassic reptiles of Europe
Jurassic England
Fossils of England
Oxford Clay
Jurassic France
Fossils of France
Fossil taxa described in 2013