Duerosuchus
Encyclopedia
Duerosuchus is an extinct genus
of crocodilian. Remains have been found from Corrales del Vino
in Zamora, Spain
, and are middle Eocene
in age (about 40 million years old). Duerosuchus is known from a single skull that is incomplete but otherwise well preserved, as well as a lower jaw, some osteoderm
s, and possibly some vertebrae.
Duerosuchus is a basal
crocodilian thought to be closely related to brevirostrine, or short snouted crocodilians, such as alligatoroids. However, the genus has not yet been included in a phylogenetic study and its position within Crocodilia
is uncertain.
. The remains were discovered by Luis Alonso Andrés and his son Luis Alonso Santiago, two amateur paleontologists. The genus was first described by Andrés and Santiago in 2009 and was named after the Duero River, as it was found in the Duero River Basin. The type species
is D. piscator, named in reference to its presumed ability to catch fish, inferred from the shape of its teeth.
skull, known as STUS 14.133, is missing some bones such as those surrounding the infratemporal fenestra on the back side of the skull and the nasal bone
along the midline of the snout. Despite the lack of some material, the shape of the skull can be inferred from existing bones. The teeth are sharp and recurved with narrow bases. There is a notch in the premaxilla
to accommodate the fourth mandibular tooth of the lower jaw.
n Iberosuchus
and the crocodilians Asiatosuchus
and Diplocynodon
. Asiatosuchus, a large crocodylid, probably had a similar lifestyle to Duerosuchus. Asiatosuchus, like other large crocodilians, had robust back teeth that were suitable for crushing. It may have preyed on turtles such as Allaeochelys
that were present in the area. While Duerosuchus may also have preyed on turtles, it was better adapted to catching smaller prey such as fish. Fish are abundant in the sediments from which Duerosuchus has been found. The University of Salamanca has a collection of Eocene fossils from the area that includes remains of Duerosuchus, Asiatosuchus, Iberosuchus, and many fish and turtle fossils, some of which have bite marks thought to have been made by crocodilians.
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 crocodilian. Remains have been found from Corrales del Vino
Corrales del Vino
Corrales del Vino is a municipality in the province of Zamora, ....
in Zamora, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, and are middle Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
in age (about 40 million years old). Duerosuchus is known from a single skull that is incomplete but otherwise well preserved, as well as a lower jaw, some osteoderm
Osteoderm
Osteoderms are bony deposits forming scales, plates or other structures in the dermal layers of the skin. Osteoderms are found in many groups of extant and extinct reptiles, including lizards, various groups of dinosaurs , crocodilians, phytosaurs, aetosaurs, placodonts, and hupehsuchians...
s, and possibly some vertebrae.
Duerosuchus is a basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
crocodilian thought to be closely related to brevirostrine, or short snouted crocodilians, such as alligatoroids. However, the genus has not yet been included in a phylogenetic study and its position within Crocodilia
Crocodilia
Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...
is uncertain.
Discovery
Remains of Duerosuchus were unearthed by an excavation team from the University of SalamancaUniversity of Salamanca
The University of Salamanca is a Spanish higher education institution, located in the town of Salamanca, west of Madrid. It was founded in 1134 and given the Royal charter of foundation by King Alfonso IX in 1218. It is the oldest founded university in Spain and the third oldest European...
. The remains were discovered by Luis Alonso Andrés and his son Luis Alonso Santiago, two amateur paleontologists. The genus was first described by Andrés and Santiago in 2009 and was named after the Duero River, as it was found in the Duero River Basin. The type species
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...
is D. piscator, named in reference to its presumed ability to catch fish, inferred from the shape of its teeth.
Description
The skull of Duerosuchus is around 20 centimetres (7.9 in) long. The length of the entire animal is estimated to have been around 160 centimetres (63 in). This estimation is based on the size of the body relative to the skull in similar crocodilians where the body length is known. The holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
skull, known as STUS 14.133, is missing some bones such as those surrounding the infratemporal fenestra on the back side of the skull and the nasal bone
Nasal bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.Each has two surfaces and four borders....
along the midline of the snout. Despite the lack of some material, the shape of the skull can be inferred from existing bones. The teeth are sharp and recurved with narrow bases. There is a notch in the premaxilla
Premaxilla
The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....
to accommodate the fourth mandibular tooth of the lower jaw.
Paleobiology
In addition to Duerosuchus, three other Eocene crocodyliforms are known from Coralles: the sebeciaSebecia
Sebecia is an extinct clade of mesoeucrocodylian crocodyliforms that includes peirosaurids and sebecids. It was first constructed in 2007 to include Hamadasuchus, Peirosauridae, and Sebecus. It was initially considered to be the sister taxon of the clade Neosuchia, which includes living...
n Iberosuchus
Iberosuchus
Iberosuchus is an extinct genus of sebecid mesoeucrocodylian from the Eocene of western Europe. It was described in 1975 by Antunes from remains from Portugal as a sebecosuchian crocodilian. The type species is I. macrodon...
and the crocodilians Asiatosuchus
Asiatosuchus
Asiatosuchus is an extinct genus of large crocodilian. It is believed to have been a basal crocodile. Specimens have been found from Russia, Belgium, France, Germany, Mongolia, and possibly Pakistan. It existed from the Danian stage of the early Paleocene epoch to the Lutetian stage of the Eocene...
and Diplocynodon
Diplocynodon
Diplocynodon is an extinct genus of alligatoroid that lived during the Paleocene to middle Miocene 49 million years ago in Europe. It looked very similar to the modern caiman in that it was small and had bony armour scutes covering its neck, back, belly, and tail...
. Asiatosuchus, a large crocodylid, probably had a similar lifestyle to Duerosuchus. Asiatosuchus, like other large crocodilians, had robust back teeth that were suitable for crushing. It may have preyed on turtles such as Allaeochelys
Allaeochelys
Allaeochelys is an extinct genus of pig-nosed turtle....
that were present in the area. While Duerosuchus may also have preyed on turtles, it was better adapted to catching smaller prey such as fish. Fish are abundant in the sediments from which Duerosuchus has been found. The University of Salamanca has a collection of Eocene fossils from the area that includes remains of Duerosuchus, Asiatosuchus, Iberosuchus, and many fish and turtle fossils, some of which have bite marks thought to have been made by crocodilians.