''Saltoposuchus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of small (1-1.5 m and 10-15 kg), long-tailed

crocodylomorph Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. During Mesozoic and early Cenozoic times, cro ...

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

(

Sphenosuchia Sphenosuchia is a suborder of basal crocodylomorphs that first appeared in the Triassic and occurred into the Middle Jurassic. Most were small, gracile animals with an erect limb posture. They are now thought to be ancestral to crocodyliforms, a ...

), from the

Norian The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian. Stratigraphic defi ...

(

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

) of Europe. The name translated means "leaping foot crocodile". It has been proposed that ''

Terrestrisuchus ''Terrestrisuchus'' is an extinct genus of very small early crocodylomorph that was about long. Fossils have been found in Wales and Southern England and date from near the very end of the Late Triassic during the Rhaetian, and it is known by t ...

gracilis'' and ''Saltoposuchus connectens'' represent different ontogenetic stages of the same genus. ''Saltoposuchus'' was commonly (and incorrectly) referred to in popular literature as the ancestor (or close ancestors) to dinosaurs, however, recent scientific research show that this is not the case.

Description and Paleobiology

Fossil evidence of Sphenosuchia and early crocodylomorphs lead paleontologists to conclude that ''Saltoposuchus'' is a terrestrial animal. As a monophyletic group of crocodylomorphs, Saltoposuchidae have many key morphological traits shared with most crocodylomorphs.

Skull

Much like other crocodylomorphs, ''Saltoposuchus'' skulls had a (reduced)

antorbital fenestra An antorbital fenestra (plural: fenestrae) is an opening in the skull that is in front of the eye sockets. This skull character is largely associated with archosauriforms, first appearing during the Triassic Period. Among extant archosaurs, birds ...

, an overhanging

squamosal bone The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

, and a medially shifted, forwards sloping quadrate and quadratojugal.Benton, Michael. "Vertebrate Palaeontology." ''Google Books''. N.p., n.d. Web. 06 Mar. 2017. https://books.google.com/books?id=VThUUUtM8A4C&pg=PA145&lpg=PA145&dq=saltoposuchus+skull&source=bl&ots=eOTIrI7iZv&sig=CFdJgVGtBssg6NSGqwNwEcpLUpQ&hl=en&sa=X&ved=0ahUKEwiEx5DKhsPSAhWqjlQKHd1oB2MQ6AEIPzAI#v=onepage&q=saltoposuchus%20skull&f=falseClarke, James M., Xing Xu, Catherine A. Forster, and Yuan Wang. "A Middle Jurassic ‘sphenosuchian’ from China and the Origin of the Crocodylian Skull." Letters to Nature (2004): 1021-024. Nature Publishing Group, 26 Aug. 2004. Web. 6 Mar. 2017. http://www.ivpp.ac.cn/qt/papers/201403/P020140313398876087117.pdf ''Saltoposuchus'' have a long pointed skull and slender pointed teeth. The pointed teeth of ''Saltoposuchus'' indicate that this species is most likely carnivorous. At the back of the skull, ''Saltoposuchus'' share many specializations of crocodylomorphs including a square skull table made out of post-orbital and

s which overhangs the temporal region, a lateral mandibular fenestra, and a cheek region that is overhung by the squamosal. In ''Sphenosucians'', the quadrate head makes contact with the prootic and squamosal bones.

Skeleton

''Saltoposuchus'' a long backward pointing spine at the

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...

. Another key feature of ''Saltoposuchus'' includes a non-preforated

acetabulum The acetabulum (), also called the cotyloid cavity, is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint. Structure There are three bones of the ''os coxae'' (hip bone) that c ...

(hip joint), which is a defining characteristic of all dinosaurs. ''Saltoposuchus'' were also considered to be bipedal based on its skeletal constitution, but could walk on all four limbs as well, making it a

facultative biped A facultative biped is an animal that is capable of walking or running on two legs (bipedal), as a response to exceptional circumstances ( facultative), while normally walking or running on four limbs or more. In contrast, obligate bipedalism is ...

. ''Saltoposuchus'' also had a double row of bony

scute A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...

s along its back, which can be seen on modern crocodilians today. Like with other sphenosuchians and early crocodylomorphs, ''Saltoposuchus'' had fully erect slender limbs, a slender body, and long legs.Wedel, Matt. "Crocodylomorpha." Crocodylomorpha. N.p., May 2007. Web. 06 Mar. 2017. http://www.ucmp.berkeley.edu/taxa/verts/archosaurs/crocodylomorpha.php Paleontologists believe that with their body structures that ''Saltoposuchus'' were very fast and nimble. Sphenosuchians have been described as "greyhound dog with scales and a long tail." Early crocodylomorphs, such as ''Saltoposuchus'', have very long centra in their vertebrae, short vertebral processes, and medium-sized zygapophyseal joints.Molnar, Julia L., Stephanie E. Pierce, Bhart-Anjan S. Bhullar, Alan H. Turner, and John R. Hutchinson. "Morphological and Functional Changes in the Vertebral Column with Increasing Aquatic Adaptation in Crocodylomorphs." ''Royal Society Open Science''. The Royal Society, 01 Nov. 2015. Web. 06 Mar. 2017. Molnar et Al. concluded that the average mediolateral range of motion in the early crocodylomorphs was greater than dorsoventral range of motion, and dorsoventral stiffness was estimated to be higher than mediolateral stiffness. In the wrists of ''Saltoposuchus'', the radiale and ulnare are elongated into rod shaped elements instead of being button-shaped, which is a shared characteristic among crocodylomorphs.

Behavior

The ''Saltoposuchus'' is a terrestrial animal whose body was built for running at fast speeds. Based on the behavior of other species of archosaur, it is possible that the ''Saltoposuchus'' hunted in packs just like another archosaur genus, ''Coelophysis.'' Bagley, Mary. "Triassic Period Facts: Climate, Animals & Plants." LiveScience. Purch, 11 Feb. 2014. Web. 06 Mar. 2017. http://www.livescience.com/43295-triassic-period.html It is also possible that ''Saltoposuchus'' could exhibit cannibalistic behavior because a few of the ''Coelophysis'' individuals found had remains of smaller members of the species inside the larger animals. By looking at the diet of related species, we can assume that ''Saltoposuchus'' ate small lizards, insects, and mammals that existed during the Triassic Period."Fossil Record." ''Crocodylomorpha Fossil Record''. University of Bristol, n.d. Web. 06 Mar. 2017. http://palaeo.gly.bris.ac.uk/Palaeofiles/Fossilgroups/Crocodylomorpha/Fossilrecord.html

Discovery

''Saltoposuchus connectens'' and ''Saltoposuchus longipes'' were discovered and named by German paleontologist

Friedrich von Huene Friedrich von Huene, born Friedrich Richard von Hoinigen, (March 22, 1875 – April 4, 1969) was a German paleontologist who renamed more dinosaurs in the early 20th century than anyone else in Europe. He also made key contributions about v ...

in 1921. Both species were found in the Burrer Quarry, Pfaffenhofen, which is an Alaunian terrestrial sandstone/marl in the

Löwenstein Formation The Löwenstein Formation (Stubensandstein in Baden-Württemberg, Burgsandstein in Bavaria) is a lithostratigraphic formation of the Keuper in Germany. It is underlain by the Mainhardt Formation and overlain by the Trossingen Formation. It dates ...

of south-west Germany. The Löwenstein Formation has been dated back to 215.6 - 212.0 Ma, which dates back to the Late Triassic Period. Fossils have also been found in the

Trossingen Formation The Trossingen Formation, formerly the Knollenmergel, is a geological formation in Germany and Switzerland. It dates back to the late Norian-Rhaetian.Weishampel et al., 2004, pp.521–525 Vertebrate paleofauna See also * List of dinosaur- ...

(also located in Germany), and the

Lossiemouth Sandstone The Lossiemouth Sandstone is a Middle to Late Triassic (Ladinian to Norian) age geological formation. It is exposed on the south side of the Moray Firth near Lossiemouth and near Golspie in Sutherland. Dinosaur remains are among the fossils tha ...

formation.

Geographical/Historical Information

Fossils found in Germany indicate that ''Saltoposuchus'' existed in Europe, or more appropriately,

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

. The

Mesozoic Era The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising ...

has been regarded as " The Age of Reptiles" so ''Saltoposuchus'' lived among many different species including the earliest species of

pterosaurs Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

and other bipedal reptilians.

Archosaur Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian d ...

s, the ancestor to Crocodylomorpha, made its first appearance in the middle of the Triassic era. This is also the period in which the earliest mammals started appearing.

Therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s dominated the Early - Middle Triassic Period, but as time went on, therapsids started becoming extinct and archosaurs became the dominant group of reptiles. After the

Permian–Triassic extinction event The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as ...

wiped out 90% of species in the world,Society, National Geographic. "Triassic Period, Mesozoic Era Information, Dinosaur Facts." ''National Geographic''. N.p., n.d. Web. 06 Mar. 2017. http://science.nationalgeographic.com/science/prehistoric-world/triassic/ conifer forests started to recover, species started occupying and thriving in newly found ecological niches,

Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

started splitting into Laurasia and

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

, and the air was very arid with hot summers and cold winters. After marine life had been wiped out by the mass extinction event, the Triassic waters were populated with very few families of fish. The Triassic Period showed the first development of modern stony corals and a time of modest reef building activity in the shallower waters of the Tethys near the coasts of Pangaea. During the Mesozoic Era, early mammals, reptilian species, and other insects populated the land. Insects that had survived the mass extinction and were existing during this time include spiders, scorpions, millipedes, centipedes, and a newer group of beetles. Cladogram of crocodylomorphs

Related Species

Sister groups to ''Saltoposuchus'' include ''

Gracilisuchus ''Gracilisuchus'' (meaning "slender crocodile") is an extinct genus of tiny pseudosuchian (a group which includes the ancestors of crocodilians) from the Late Triassic of Argentina. It contains a single species, ''G. stipanicicorum'', which is pl ...

'', '' Hesperosuchus'', '' Dromicosuchus'', ''

Dibothrosuchus ''Dibothrosuchus'' is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from several partial skeletons and skulls. These fossils were found in Lower Jurassic ...

'', ''

Litargosuchus ''Litargosuchus'' is a sphenosuchian Crocodylomorpha, crocodylomorph, a Basal (phylogenetics), basal member of the Crocodylomorpha, crocodylomorph clade from the Early Jurassic of South Africa. Its genus name ''Litargosuchus'' is derived from Gre ...

'', ''

Kayentasuchus ''Kayentasuchus'' (meaning "Kayenta Formation crocodile") is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from a single skeleton found in rocks of the Si ...

''. These genus are found in the late Triassic to the earlier Jurassic eras. All of these genus are part of the ''Sphenosuchia'' clade and they all have similar morphology and stature. ''Sphenosuchia'' are ancestors to

crocodyliformes Crocodyliformes is a clade of 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 only pseudo ...

, which constitute modern crocodilians. Modern crocodylia reacquired semi-aquatic life style. Research has disputed the reasoning for how crocodyliformes reacquired semi-aquatic traits, and the forefront explanation the changes in osteoderm and rib morphology over crocodylomorph evolution affected the stiffness of the vertebral columns, which would allow for better movement in semi-aquatic environments.

''Gracilisuchus''

This group has species that are approximately 0.3 meters long and is classified as a primitive sphenosuchian. Like ''Saltoposuchus,'' this species was thought to have been able to run on its slim hindlegs. This group of reptiles had a disproportionately large head, strong jaws, and bony plates extending from the back to the tail. It most likely ate small lizards.

''Terrestrisuchus''

This group's specimens are around 0.5 meters long. Similarly to ''Saltoposuchus'', ''Terrestrisuchus'' were known to have a delicate frame and could run at fast speeds for long distances.

''Litargosuchus & Kayentasuchus''

Two early crocodylamorph species that are sister groups to ''Saltoposuchus''. They share many similar traits and morphology with ''Saltoposuchus'' and the discovery of these groups convinced Paleontologists that these genus are not monophyletic with ''Sphenosuchus'' (not to be confused with the suborder ''Sphenosuchia'').Clark, James M., and Hans‐Dieter Sues. "Two New Basal Crocodylomorph Archosaurs from the Lower Jurassic and the Monophyly of the Sphenosuchia." ''Zoological Journal of the Linnean Society''. Blackwell Science Ltd, 21 Aug. 2002. Web. 06 Mar. 2017. http://onlinelibrary.wiley.com/doi/10.1046/j.1096-3642.2002.00026.x/pdf

References

External links

Palaeos

Clarke
{{Taxonbar, from=Q3499325 Triassic crocodylomorpha Terrestrial crocodylomorphs Late Triassic reptiles of Europe Triassic archosaurs Late Triassic archosaurs Taxa named by Friedrich von Huene Fossil taxa described in 1921 Prehistoric pseudosuchian genera