''Sinomacrops'' is a

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 ...

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 ...

anurognathid Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: ''Anurognathus'', from the Late Jurassic of Germany; ''Jeholop ...

pterosaur 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 ...

from the Middle to

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

periods of what is now the Daohugou Beds of the

Tiaojishan Formation The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of ...

in Mutoudeng, Qinglong County of the

Hebei Hebei or , (; alternately Hopeh) is a northern province of China. Hebei is China's sixth most populous province, with over 75 million people. Shijiazhuang is the capital city. The province is 96% Han Chinese, 3% Manchu, 0.8% Hui, an ...

province. The remains of ''Sinomacrops'' date back to around 164 to 158 million years ago. The type and only known species is ''Sinomacrops bondei''.

Etymology

''Sinomacrops'' derives from the

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

word roots ''Sino~'', referring to

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, ''macro~'' (''makros''), meaning large, and ''ops'', meaning eyes/face. The name ''Sinomacrops'' is in reference to both the large eyes of and the broad faces that are typical of the family

Anurognathidae Anurognathidae is a family (biology), family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: ''Anurognathus'', from the Late Jurassic of G ...

, as well as to the Chinese origin of the

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''bondei'', honors

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Niels Bonde.

Description

''Sinomacrops'' exhibits two

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

(distinguishing traits) that distinguish it from other pterosaurs: one of them is having the first three

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates 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 t ...

alveoli Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ** Alveolar macrophage * ...

(tooth sockets) closely spaced, and the other one is having the

tibiotarsus The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia. A similar structure also occurred in the Mesozoic Heterodontosauridae. These sm ...

twice as long as the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen of ''Sinomacrops'', JPM-2012-001, consists of a crushed skeleton. The preserved bone tissue of skeleton shows a fragile, brittle condition. Due to this, in many parts of the skeleton, bone tissue fragments have been lost after the specimen was collected. These fragments that were lost left clear impressions on the matrix, which indicated their original location on the skeleton. Fragments of ''Sinomacrops'' that were lost include mainly the

caudal vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

, the

sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...

, the distal (away from the point attachment)

epiphysis The epiphysis () is the rounded end of a long bone, at its joint with adjacent bone(s). Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate). At the join ...

(rounded end of a long bone) of the right

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, proximal (near the point of attachment) epiphyses of both the right

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

and

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

, parts of the left

, as well as most of the left manus (hand). The skeleton of ''Sinomacrops'' includes patches of soft tissue. A strange patch of soft tissue lateral (to the side) to the left tibiotarsus suggests that the brachiopatagium ("arm-membrane") extended to the rear onto the distal part of the lower leg. A brachiopatagium extending to the rear of the lower leg is also present in the species ''

Jeholopterus ninchengensis ''Jeholopterus'' was a small anurognathid pterosaur from the Middle to Late Jurassic Daohugou Beds of the Tiaojishan Formation of Inner Mongolia, China, preserved with hair-like pycnofibres and skin remains. Naming The genus was named in 2002 ...

'', which is a close relative of ''Sinomacrops'', this feature also appears in all pterosaurs in general.

Classification

In its description in 2021, Wei and colleagues assigned ''Sinomacrops'' to the subfamily

Batrachognathinae Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: ''Anurognathus'', from the Late Jurassic of Germany; ''Jeholopt ...

, a subfamily within the family

. Within the family, ''Sinomacrops'' was the sister taxon to the pterosaur ''

Batrachognathus ''Batrachognathus'' is an extinct genus of anurognathid pterosaur from the Late Jurassic ( Oxfordian to Kimmeridgian) Karabastau Formation of the central Asian republic of Kazakhstan. The genus was named in 1948 by the Russian paleontologist Ana ...

''. Below is a cladogram representing their

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

References

{{Taxonbar, from=Q106303603 Monofenestratans Fossil taxa described in 2021