''Phyllodontosuchus'' (

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

, meaning "leaf tooth crocodile", in reference to the shape of the middle and posterior teeth) is a

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 ...

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 ...

n, a type of basal

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. Extinct crocodylomorphs were considerably mor ...

, the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

that comprises the

crocodilia Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchia ...

ns and their closest kin. It is known from a skull and jaws from

Lower Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic–Jurassic extinction event, 201.3 Ma&nb ...

rocks of

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. ''Phyllodontosuchus'' is unusual because some of its teeth were leaf-shaped, like those of some

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s, and it does not appear to have been a strict

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

like most other crocodylomorphs.

History and description

''Phyllodontosuchus'' is based on BVP568-L12, a crushed skull and jaws recovered from the

Sinemurian In the geologic timescale, the Sinemurian is an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between 199.5 ±0.3 annu ...

-age Dark Red Beds of the

Lufeng Formation The Lufeng Formation (formerly Lower Lufeng Series) is a Lower Jurassic sedimentary rock formation found in Yunnan, China. It has two units: the lower Dull Purplish Beds/Shawan Member are of Hettangian age, and Dark Red Beds/Zhangjia'ao Member a ...

near Dawa in Yunnan. A ''

Morganucodon ''Morganucodon'' ("Glamorgan tooth") is an early mammaliaform genus that lived from the Late Triassic to the Middle Jurassic. It first appeared about 205 million years ago. Unlike many other early mammaliaforms, ''Morganucodon'' is well represent ...

'' skull was also recovered from this locality. BVP568-L12 is only long and imperfectly preserved; it was first thought to represent an early

ornithischia Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek ...

n dinosaur. Sutures are not visible, so despite the small size, the specimen appears to have come from an adult. ''Phyllodontosuchus'' was named in 2000 by Jerald Harris and colleagues. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

is ''P. lufengensis'', in reference to the Lufeng Formation. There were 17 or 18 teeth per side in the upper jaw, which differed in

shape A shape is a graphics, graphical representation of an object's form or its external boundary, outline, or external Surface (mathematics), surface. It is distinct from other object properties, such as color, Surface texture, texture, or material ...

depending on where they were in the jaw (

heterodont In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology. Human dentition is heterodont and diphyodont as an example. In vertebrates, heterodont pertains to animals wher ...

y). The first five or six were pointed, conical, and curved backward. The following twelve were leaf- or spade-shaped, with fine crenelations on the trailing edge. These are similar to the teeth of some

prosauropod Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the Sauropoda, sauropods and their ancestral relatives. Sauropods generally grew to very large siz ...

s and early ornithischians, but differ in important features. For example, the teeth lacked the swellings and ridges seen in the teeth of early ornithischians like ''

Lesothosaurus ''Lesothosaurus'' is a Monotypic taxon, monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from L ...

'', and the coarse denticles (smaller points) of leaf-shaped ornithischian and prosauropod teeth in general. ''Phyllodontosuchus'' also lacked a

predentary Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Ancient ...

as found in all known ornithischians. Instead, it is most similar to sphenosuchians. Heterodonty is known in several sphenosuchians, including ''

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 ...

'', ''

Hesperosuchus ''Hesperosuchus'' is an extinct genus of crocodylomorph reptile that contains a single species, ''Hesperosuchus agilis''. Remains of this pseudosuchian have been found in Late Triassic (Carnian) strata from Arizona and New Mexico.Colbert, E. H. 1 ...

'', '' Pedeticosaurus'', and ''

Sphenosuchus ''Sphenosuchus'' ("wedge crocodile") is an extinct genus of crocodylomorph from the Early Jurassic Elliot Formation of South Africa, discovered and described early in the 20th century. The skull is preserved very well but other than elements of t ...

''. These forms had similar divisions of pointed and recurved anterior teeth and less pointed middle and posterior teeth, which could have been the ancestral state for the leaf-shaped teeth of ''Phyllodontosuchus''. Small heterodont crocodylomorphs are known from other lineages as well, including '' Edentosuchus'', '' Chimaerasuchus'', and ''

Malawisuchus ''Malawisuchus'' (meaning "Malawi crocodile") is an extinct genus of notosuchian mesoeucrocodylian from the Early Cretaceous Dinosaur Beds of Malawi. It was described in 1997 by Elizabeth Gomani as a member of the family Notosuchidae. The type ...

''. These small, variably-toothed crocodylomorphs are thought to have had diets beyond the typical carnivory/

piscivory A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted repti ...

of modern crocodilians, possibly including some degree of herbivory. If ''Phyllodontosuchus'' did eat plants, it probably did not grind them in the jaws, though.

Notes

The tooth count in the abstract and diagnosis is 6 conical teeth and 12 leaf-shaped teeth, while the body of the paper describes a total of 17 teeth per side, ?5 of which are conical.

References

{{Taxonbar, from=Q7188818 Early Jurassic reptiles of Asia Early Jurassic crocodylomorphs Prehistoric pseudosuchian genera