Lusitanisuchus
Encyclopedia
Lusitanisuchus is an extinct genus
of mesoeucrocodylia
n crocodylomorph
. Mostly fragmentary fossil
s have been found from several localities in Portugal
and are Late Jurassic
and Early Cretaceous
in age.
The type
and only species
, Lusitanisuchus mitracostatus, was named in 2004 after having previously been described as a species of the genus Lisboasaurus
. L. mitracostatus was originally thought to have been an anguimorph
lizard
upon its naming in 1970 based on fragmentary jaw remains and isolated teeth found from the Kimmeridgean-age Guimarota Formation
in Leiria
. The species was later regarded as a nomen dubium
by several authors of papers regarding Lisboasaurus due to the incomplete nature of the known remains associated with the species. However, a later reexamination of fossils from the Guimarota Formation had found skull material that included a dentary similar to the one seen in the holotype of L. mitracostatus. These remains, being more complete than those of the holotype, showed that L. mitracostatus was really a crocodylomorph rather than an anguimorph. Furthermore, it was shown to be a genus distinct from Lisboasaurus, which had by then been shown to be a crocodylomorph as well.
Several teeth referable to Lusitanisuchus were also found from Porto Dinheiro
, Lourinhã
in strata deposited during the Berriasian
stage of the Early Cretaceous, extending the temporal range of this taxon by about 15 Ma.
such as Aviatyrannis
and Stokesosaurus
, the ornithopod Phyllodon
, and the small coelurosaur
Compsognathus
. The Porto Dinheiro locality included dinosaurs such as the diplodocid Dinheirosaurus
as well as early mammals such as Portopinheirodon.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of mesoeucrocodylia
Mesoeucrocodylia
Mesoeucrocodylia is the name of the clade that includes Eusuchia and the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day....
n crocodylomorph
Crocodylomorpha
The Crocodylomorpha are an important group of archosaurs that include the crocodilians and their extinct relatives.During Mesozoic and early Tertiary times the Crocodylomorpha were far more diverse than they are now. Triassic forms were small, lightly built, active terrestrial animals. These were...
. Mostly fragmentary fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s have been found from several localities in Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
and are Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
and Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
in age.
The type
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
and only species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, Lusitanisuchus mitracostatus, was named in 2004 after having previously been described as a species of the genus Lisboasaurus
Lisboasaurus
Lisboasaurus is a small genus of Mesozoic crocodylomorph that lived in fresh water. It is known from fossilized tooth and jaw fragments of Late Jurassic and Early Cretaceous age. Two species have been described. In the past Lisboasaurus has been interpreted as a Mid Jurassic avialan, troodontid,...
. L. mitracostatus was originally thought to have been an anguimorph
Anguimorpha
Anguimorphs of the infraorder Anguimorpha include the anguids , monitor lizards, the extinct mosasaurs, and helodermatids . The infraorder was named by Fürbringer in 1900 to include all autarchoglossans closer to Varanus and Anguis than Scincus...
lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
upon its naming in 1970 based on fragmentary jaw remains and isolated teeth found from the Kimmeridgean-age Guimarota Formation
Camadas de Guimarota
The Camadas de Guimarota is a geological formation in Europe, and the synonym of "Camadas de Alcobaça". It dates back to the Late Jurassic.-Vertebrate fauna:...
in Leiria
Leiria (district)
The District of Leiria is located in Central Portugal. The District Capital is the city of Leiria which is also the largest city and most populous city.The district is composed by 16 municipalities:[C = city/cidade T = town/vila]...
. The species was later regarded as a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
by several authors of papers regarding Lisboasaurus due to the incomplete nature of the known remains associated with the species. However, a later reexamination of fossils from the Guimarota Formation had found skull material that included a dentary similar to the one seen in the holotype of L. mitracostatus. These remains, being more complete than those of the holotype, showed that L. mitracostatus was really a crocodylomorph rather than an anguimorph. Furthermore, it was shown to be a genus distinct from Lisboasaurus, which had by then been shown to be a crocodylomorph as well.
Several teeth referable to Lusitanisuchus were also found from Porto Dinheiro
Porto Dinheiro
Porto Dinheiro is a locality in the county of Ribamar, municipality of Lourinhã, in Portugal.It is known as a rich fossil locality, from where were found many Late Jurassic dinosaurs and mammals...
, Lourinhã
Lourinhã
Lourinhã is a municipality in Portugal with a total area of 147.2 km² and a total population of 24,601 inhabitants. The seat of the municipality is the village of Lourinhã, with a population of 8,800 inhabitants....
in strata deposited during the Berriasian
Berriasian
In the geological timescale, the Berriasian is an age or stage of the Early or Lower Creteceous. It is the oldest or lowest subdivision in the entire Cretaceous. It spanned between 145.5 ± 4.0 Ma and 140.2 ± 3.0 Ma...
stage of the Early Cretaceous, extending the temporal range of this taxon by about 15 Ma.
Paleobiology
Lusitanisuchus coexisted with many dinosaurs from the Lusitanian Basin during the Late Jurassic and Early Cretaceous. Dinosaur fossils found from the Guimarota Formation include tyrannosauroidsTyrannosauroidea
Tyrannosauroidea is a superfamily of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent beginning in the Jurassic Period...
such as Aviatyrannis
Aviatyrannis
Aviatyrannis is a genus of tyrannosauroid dinosaur from the Kimmeridgian stage of the Late Jurassic found in Portugal. It was described by Oliver Rauhut in 2003. The name means "Jurassic grandmother tyrant"...
and Stokesosaurus
Stokesosaurus
Stokesosaurus is a genus of small , early tyrannosaur from the Late Jurassic period of Utah and England. It was named after Utah geologist William Lee Stokes...
, the ornithopod Phyllodon
Phyllodon
Phyllodon was a genus of small ornithopod dinosaur from the Kimmeridgian-age Upper Jurassic Guimarota Formation of Leiria, Portugal. It may have been closely related to contemporaneous dinosaurs in North America....
, and the small coelurosaur
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...
Compsognathus
Compsognathus
Compsognathus was a small, bipedal, carnivorous theropod dinosaur. The animal was the size of a turkey and lived around 150 million years ago, the early Tithonian stage of the late Jurassic Period, in what is now Europe. Paleontologists have found two well-preserved fossils, one in Germany...
. The Porto Dinheiro locality included dinosaurs such as the diplodocid Dinheirosaurus
Dinheirosaurus
Dinheirosaurus is a genus of diplodocid sauropod dinosaur. It has been found in the upper section of the Late Jurassic strata of the Camadas de Alcobaça Formation located in central-western Portugal at Porto Dinheiro, Lourinhã...
as well as early mammals such as Portopinheirodon.