''Smok'' (meaning "dragon" in
Polish) 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 large
carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...
archosaur
Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics ...
. It lived during the
latest Triassic period (latest
Norian
The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...
to early
Rhaetian
The Rhaetian is the latest age (geology), age of the Triassic period (geology), Period (in geochronology) or the uppermost stage (stratigraphy), stage of the Triassic system (stratigraphy), System (in chronostratigraphy). It was preceded by the N ...
stage, between 208.5–205
Ma). Its remains have been found in
Lisowice, southern
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...
. The
only species is ''Smok wawelski'' (after the
Wawel Dragon, a dragon from Polish folklore) and was named in
2012
2012 was designated as:
*International Year of Cooperatives
*International Year of Sustainable Energy for All
Events January
*January 4 – The Cicada 3301 internet hunt begins.
* January 12 – Peaceful protests begin in the R ...
. It is larger than any other known predatory archosaur from the Late Triassic or Early Jurassic of central Europe. The relation of ''Smok'' to other archosaurs has not yet been thoroughly studied; it may be a
rauisuchid,
prestosuchid, an
ornithosuchid pseudosuchia
Pseudosuchia, from Ancient Greek ψεύδος (''pseúdos)'', meaning "false", and σούχος (''soúkhos''), meaning "crocodile" is one of two major divisions of Archosauria, including living crocodilians and all archosaurs more closely relat ...
n (part of the crocodilian lineage of archosaurs) or a
theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
dinosaur.
Description

At an estimated in length, ''Smok'' was the largest carnivorous archosaur in central Europe in the time it was alive. It was larger than any other known
theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
dinosaur or
pseudosuchia
Pseudosuchia, from Ancient Greek ψεύδος (''pseúdos)'', meaning "false", and σούχος (''soúkhos''), meaning "crocodile" is one of two major divisions of Archosauria, including living crocodilians and all archosaurs more closely relat ...
n living in central Europe during either the Late Triassic or Early Jurassic. The skull is long.
[
Several features indicate that ''Smok'' is an ]archosaur
Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics ...
, including serrated teeth, a contact between the jugal
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species.
Anatomy ...
and quadratojugal The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians.
Anatomy and function
In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and ...
bones at the back of the skull, a hole in front of the eye socket called the 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 Archosauriformes, archosauriforms, first appearing during the Triassic Period. Among Extant ...
, maxilla
In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...
e bones in the upper jaw that connect along their palatal
The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity.
A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sepa ...
processes, and a rounded projection on the upper part of the femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg.
The Femo ...
bone.[
The ]braincase
In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calv ...
of ''Smok'' includes many derived (advanced) features. The most prominent of these is a funnel-shaped structure on the bottom of the braincase, formed by a very wide, rounded basisphenoid bone. A deep notch called the basisphenoid recess cuts into the back of this funnel. Above the funnel is a very thin area of the braincase that is formed by deep depressions on the basisphenoids.[
]
''Smok'' has several features that are shared with both dinosaurs and crocodile-line archosaurs, making classification difficult. Similarities with theropods include a groove, or antitrochanter, on the ilium bone of the hip that is part of the acetabulum
The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:concave, concave surface of the pelvis. The femur head, head of the femur meets with the pelvis at the acetabulum, forming the Hip#Articulation, hip joint.
Structure
The ...
(a depression where the head of the femur attaches to the hip). ''Smok'' and theropods also have an anterior trochanter
A trochanter is a tubercle of the femur near its joint with the hip bone. In humans and most mammals, the trochanters serve as important muscle attachment sites. Humans have two, sometimes three, trochanters.
Etymology
The anatomical term ' ...
on the femur. Some large theropods share with ''Smok'' the deep depressions of the basisphenoids in the braincase. Similarities with rauisuchians include a triangular antorbital fenestra and a connection between the ectopterygoid and jugal bones of the skull that is split into two projections. The hip of ''Smok'' has a ridge on the lateral surface of the ilium above the acetabulum. This ridge is a defining characteristic of rauisuchians, forming a buttress over the femur and giving these animals a pillar-erect stance.[
Other features of ''Smok'' seem to exclude it from these groups of archosaurs. The ]premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...
and maxilla of the upper jaw attach closely to each other, making a continuous row of evenly spaced teeth. Early theropods and orthithosuchids have a toothless gap between the premaxilla and the maxilla, distinguishing them from ''Smok''. The upper jaw bones of rauisuchians are not closely connected, leaving a small opening between the premaxilla and maxilla that is not seen in ''Smok''. Unlike many pseudosuchids and theropods, ''Smok'' does not have pneumatic areas, or air pockets, in the braincase. It also has several features that link it with primitive archosauromorphs, including the presence of a postfrontal bone The postfrontal is a paired cranial bone found in many tetrapods. It occupies an area of the skull roof between and behind the orbits (eye sockets), lateral to the frontal and parietal bones, and anterior to the postorbital bone.
The postfrontal ...
on the skull and a closed acetabulum in the hip.[
]
Discovery and naming
''Smok'' was found in a locality near Lisowice village that is latest Norian
The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...
to early Rhaetian
The Rhaetian is the latest age (geology), age of the Triassic period (geology), Period (in geochronology) or the uppermost stage (stratigraphy), stage of the Triassic system (stratigraphy), System (in chronostratigraphy). It was preceded by the N ...
in age. This area was known to contain Triassic fossils since it was formally described in 2008. The first material of ''Smok'', the jawbone and fragments of the skull, was discovered in 2007. It was first described in 2008 as a theropod dinosaur based on features in its braincase and frontal bone
In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...
. The material was also thought to represent two individuals. Similarities were noted between the braincase of the animal and that of allosauroids. When the discovery was first announced, it was called "the Dragon of Lisowice" and was purported to be the first member of a line of dinosaurs that led to ''Tyrannosaurus rex
''Tyrannosaurus'' () is a genus of large theropoda, theropod dinosaur. The type species ''Tyrannosaurus rex'' ( meaning 'king' in Latin), often shortened to ''T. rex'' or colloquially t-rex, is one of the best represented theropods. It live ...
''. Bones from other parts of the body were found in 2009 and 2010. Five tracks made by a three-toed archosaur – presumably a theropod dinosaur – were found in rocks that were above the layer where ''Smok'' was found. The footprints may belong to ''Smok'', but the lack of foot bones in the skeleton make this association uncertain.[
]
''Smok'' is known from the holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...
ZPAL V.33/15, a partially complete braincase which is associated with a partially preserved skeleton
A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal fra ...
, including cranial
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Thi ...
and postcrania
The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...
l bones from the referred materials ZPAL V.33/16-56, 97-102, 295-314, 434 and 507. All specimens were found in the same location (Lipie Śląskie clay-pit Lipie may refer to the following places:
*Lipie, Kuyavian-Pomeranian Voivodeship (north-central Poland)
*Lipie, Kutno County in Łódź Voivodeship (central Poland)
*Lipie, Wałcz County in West Pomeranian Voivodeship (north-west Poland)
*Lipie, Paj ...
Formation) and probably represent a single individual. It was first named by Grzegorz Niedźwiedzki, Tomasz Sulej and Jerzy Dzik
Jerzy Dzik (born 25 February 1950) is a Polish paleontologist.
He has described many species, genera, and families of conodonts, including the Order (biology), order Ozarkodinida (in 1976).
In 2003, he described the Dinosauriformes, dinosaurifor ...
in 2012 after the mythological Polish dragon of the same name that lived in a cave near the excavation site. The cave was on Wawel Hill
The Wawel Royal Castle (; ''Zamek Królewski na Wawelu'') and the Wawel Hill on which it sits constitute the most historically and culturally significant site in Poland. A fortified residency on the Vistula River in Kraków, it was established o ...
, the namesake of the type species ''S. wawelski''.[ Other potential specimens of the genus, identified as ''Smok'' sp., have also been discovered in southern Poland.]
Paleoecology
''Smok'' was the largest predator in its environment. Other large predatory archosaurs included the dinosaur ''Liliensternus
''Liliensternus'' is an extinct genus of basal neotheropod dinosaur that lived approximately 210 million years ago during the latter part of the Triassic Period in what is now Germany. ''Liliensternus'' was a bipedal, ground-dwelling carnivore ...
'' and the rauisuchids '' Polonosuchus'' and '' Teratosaurus'', but these animals were much smaller than ''Smok''. It was one of the largest archosaurs in the world during the Late Triassic, and larger archosaurs did not appear until after the Early Jurassic. ''Smok'' lived alongside small carnivorous dinosauromorph
Dinosauromorpha is a clade of Avemetatarsalia, avemetatarsalians (archosaurs closer to birds than to crocodilians) that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include Dinosauriformes, d ...
and poposauroid archosaurs and large herbivorous dicynodonts.[
]
Paleobiology
Examination of coprolites attributed to ''Smok'' by Martin Qvarnström ''et al.,'' indicate that this archosaur was able to crush bone. Based on examination of the bone fragments within the coprolites, ''Smoks ability to retain food within its digestive system varied considerably based on prey availability and food type. The variable mixture of bones, some belonging to fish, others to dicynodonts, and to temnospondyls indicates ''Smok'' was a generalized predator. Teeth from this archosaur were also uncovered from these trace fossils, indicating it may have swallowed its own broken teeth during feeding. The heavy amounts of bone in the diet indicate that salt and marrow from the bones of herbivores and other prey items was an important component in the archosaur's diet; an important behavior often linked with modern mammalian predators but seldom studied in ancient archosaurian reptiles. The findings were published in the journal ''Scientific Reports'' in 2019.
References
{{Taxonbar, from1=Q3486846, from2=Q18707722
Late Triassic archosaurs
Fossil taxa described in 2012
Late Triassic reptiles of Europe
Fossils of Poland
Triassic Poland