Pterosaur Species Research Articles

A new gnathosaurine (Pterosauria, Archaeopterodactyloidea) from the Late Jurassic of Portugal.

An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, Lusognathus almadrava gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide.

Habitat of the giant pterosaur Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea): a paleoenvironmental reconstruction of the Javelina Formation (Upper Cretaceous) Big Bend National Park, Texas

ABSTRACT The Maastrichtian Javelina Formation of southwestern Texas comprises a thick sequence of stream channel and floodplain deposits accumulated in a broad southeast-trending valley, several hundred kilometers inland from the Late Cretaceous shoreline. Three pterosaur species are found here. Remains of Quetzalcoatlus lawsoni, sp. nov., are concentrated in deposits of shallow alkaline lakes that developed in abandoned reaches of stream channels. Areas surrounding the lakes were vegetated with fan palms, and the higher floodplain supported a subtropical forest dominated by the dicot tree Javelinoxylon and araucariacean conifers. The shallow lakes were inhabited by a diverse invertebrate fauna of arthropods, gastropods, and bivalves, a likely food source for the slender-beaked Quetzalcoatlus lawsoni, sp. nov., which may have had a lifestyle similar to modern large gregarious wading birds. In contrast, remains of the giant Q. northropi are rare and found instead only in stream channel facies. It may have had a more solitary lifestyle and preferred riparian habitats. The warm, dry, subtropical but nonseasonal conditions of the region may represent a preferred climatic regime for azhdarchid pterosaurs generally.

A new species of crested pterosaur (Pterodactyloidea, Anhangueridae) from the Lower Cretaceous (upper Albian) of Richmond, North West Queensland, Australia

ABSTRACT Pterosaur fossils from Australia are exceptionally rare. Since the discovery of the continent’s first pterosaur some 40 years ago, fewer than 20 specimens have been described. The Lower Cretaceous (upper Albian) Toolebuc Formation of North West Queensland is the most productive horizon for Australian pterosaurs. Herein, we describe a new species of pterosaur, Thapunngaka shawi gen. et sp. nov., from the Toolebuc Formation, near Richmond, North West Queensland. The specimen (KKF494) comprises the rostral portion of a crested mandible and represents the largest pterosaur yet described from Australia. The new species presents features that indicate an affinity with Anhangueridae, which is consistent with their reported cosmopolitan distribution during this period. Thapunngaka shawi can be distinguished from other anhanguerids through the possession of a mandible with a smooth dorsal surface medially and uniquely sized alveoli that are positioned laterally along the jaw. Phylogenetic analysis reveals a close relationship among all Australian anhanguerids and points to an endemic Australian radiation within Anhangueridae. Thapunngaka shawi has the largest mandibular crest of any anhanguerian worldwide, and provides further evidence for the existence of an increasingly diverse range of large crested pterosaurs in the Australian part of eastern Gondwana during the Cretaceous.

A new pterosaur species from the Lower Cretaceous of Brazil and the paleobiogeography of the Tapejaridae (Azhdarchoidea)

A new pterosaur species from the Lower Cretaceous of Brazil and the paleobiogeography of the Tapejaridae (Azhdarchoidea)

A taxonomic approach on diagnostic characters used to define new pterosaur taxa and an estimation of pterosaur diversity.

Diagnostic characters from 227 pterosaur species were listed, separated into cranial or post-cranial elements and counted. From 21 post-cranial and 23 cranial elements, most diagnostic characters were related to phalanges (15%) and rostrum. Post-cranial characters comprise 44.23%, and cranial characters 55.77% of all characters used in pterosaur diagnoses. The highest correlation between diagnostic features occurs between the coracoid and the scapula. 25.11% and 28.63% of sampled taxa were diagnosed with 3-4 and 5-6 characters, respectively. The mean number of 6.79 characters was found in specimens with both cranial and post-cranial elements, and 4.86 and 4.17 in those with just cranial or post-cranial elements, respectively. 31 from 227 species (13.7%) were erected based on single elements, which are most frequently complete or partial mandibles (n=18). We estimate that 23.4% of the total pterosaur genera are currently known, with 90% of this diversity to be unveiled up to 2145. As the requirements of broad and cautious revision of genus/group must be undertaken, and some deposits will provide mostly fragmented and incomplete material, the assignment of fairly incomplete specimens to the most inclusive taxonomic level is feasible. Tracing this scenario can guide future works on the description of new pterosaur taxa.

Laser-Stimulated Fluorescence of Aurorazhdarchid Pterosaur Shows Soft Tissues with Implications for Pterosaur Water Launch and Foraging Behaviour

Solnhofen Limestone is renowned for pterosaur discoveries including Pterodactylus, the first pterosaur species identified as a flying reptile. Here a Solnhofen aurorazhdarchid pterosaur specimen was imaged under Laser-Stimulated Fluorescence (LSF) showing its fossil soft tissues. The data recovered under LSF shows a distinct, well preserved actinofibrillar complex, an undistorted actinopatagium retaining the retrophalangeal connective tissue wedge and entire trailing edge, as well as webbed feet. These soft tissues are of particular interest for investigating water launch adaptations, because they include likely primary contact surfaces. Pterosaur launch performance has primarily focused on larger species. Here the soft tissue data supports the dynamic feasibility of small aurorazhdarchid water launch. Our model suggests that webbed feet might be an important water launch specialization, having a significant impact on launch performance. However, webbed feet appear to be plesiomorphic for most pterosaurs implying that they were probably exapted for water launch. Aquatic prey is important for many pterosaurs. The ability to water launch was likely important in all water-feeding pterosaurs. Wider future efforts to study water launch across pterosaurs should prioritise three key factors that limit its performance: available propulsive contact area, forelimb extension range and forelimb extension power about the shoulder.

First complete pterosaur from the Afro-Arabian continent: insight into pterodactyloid diversity

Despite being known from every continent, the geological record of pterosaurs, the first group of vertebrates to develop powered flight, is very uneven, with only a few deposits accounting for the vast majority of specimens and almost half of the taxonomic diversity. Among the regions that stand out for the greatest gaps of knowledge regarding these flying reptiles, is the Afro-Arabian continent, which has yielded only a small number of very fragmentary and incomplete materials. Here we fill part of that gap and report on the most complete pterosaur recovered from this continent, more specifically from the Late Cretaceous (~95 mya) Hjoûla Lagerstätte of Lebanon. This deposit is known since the Middle Ages for the exquisitely preserved fishes and invertebrates, but not for tetrapods, which are exceedingly rare. Mimodactylus libanensis gen. et sp. nov. differs from the other Afro-Arabian pterosaur species named to date and is closely related to the Chinese species Haopterus gracilis, forming a new clade of derived toothed pterosaurs. Mimodactylidae clade nov. groups species that are related to Istiodactylidae, jointly designated as Istiodactyliformes (clade nov.). Istiodactyliforms were previously documented only in Early Cretaceous sites from Europe and Asia, with Mimodactylus libanensis the first record in Gondwana.

A new species of Coloborhynchus (Pterosauria, Ornithocheiridae) from the mid-Cretaceous of North Africa

Pterosaur faunas experienced dramatic turnover between the Early and Late Cretaceous, but fossils documenting this transition are rare. The mid-Cretaceous Kem Kem beds of Morocco are one of a handful of localities preserving pterosaurs from this important interval. Previously reported taxa from the Kem Kem beds include the ornithocheirid Siroccopteryx moroccensis, the azhdarchoids Alanqa saharica and Xericeps curvirostris, an unnamed tapejarid, and a putative pteranodontid. Here, a new species of ornithocheirid, Coloborhynchus fluviferox sp. nov., is described on the basis of a well-preserved anterior rostrum fragment. It is assigned to Coloborhynchus based on the presence of an anteriorly directed first tooth pair protruding from a palatal surface, which is deflected dorsally by 90°. The new specimen differs from Siroccopteryx moroccensis and is distinguished from other species of Coloborhynchus by numerous characters, including an anterior palatal surface that defines a high isosceles triangle with two shallow, subcircular depressions located dorsal to premaxillary tooth pair one. The central region of alveoli for the first tooth pair is level with the dorsal borders of the second tooth pair and the mediodorsal crest rises steeply forming a blunt termination of the rostrum. The new species brings the number of pterosaur species from the Kem Kem beds to at least 5. The Kem Kem pterosaur assemblage resembles other Early Cretaceous faunas in having a high diversity of toothed forms, but also resembles latest Cretaceous faunas in having several edentulous azhdarchoids.

First North American occurrence of the toothed pteranodontoid pterosaur Cimoliopterus

ABSTRACTA new pterosaur species, Cimoliopterus dunni, sp. nov., is described based on a partial rostrum from the upper Cenomanian Britton Formation in the Eagle Ford Group of north-central Texas. The holotype preserves alveoli for a minimum of 26 upper teeth and bears a thin premaxillary crest that begins above the fourth pair of alveoli. The rostrum, characterized by a slight lateral flare, lacks the pronounced lateral expansion found in ornithocheirids and anhanguerids. The tip of the snout is small and blunt, and the anterior face of the rostrum is oriented posteroventrally, forming an approximately 45° angle with the anterior portion of the palate. The anteroventrally oriented first pair of alveoli is directed more ventrally than anteriorly. Phylogenetic analysis suggests that Cimoliopterus dunni and Cimoliopterus cuvieri, from the Cenomanian Grey Chalk Subgroup in Kent, England, are basal pteranodontoids that are closely related to Aetodactylus halli from the middle Cenomanian Tarrant Formation of north Texas. Cimoliopterus dunni marks only the second known occurrence of Cimoliopterus, extending its geographic range from Europe to North America. In conjunction with Coloborhynchus wadleighi from the upper Albian Pawpaw Formation, Cimoliopterus dunni provides unambiguous evidence of biogeographic linkages between the pterosaur faunas of North America and Europe in the middle Cretaceous.http://zoobank.org/urn:lsid:zoobank.org:pub:50FDA47D-0E2D-4B6E-9A18-8F04F814CE62SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Myers, T. S. 2015. First North American occurrence of the toothed pteranodontoid pterosaur Cimoliopterus. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1014904.

A new toothed pteranodontoid (Pterosauria, Pterodactyloidea) from the Jiufotang Formation (Lower Cretaceous, Aptian) of China and comments on Liaoningopterus gui Wang and Zhou, 2003

Pteranodontoids consist of a diverse and cosmopolitan clade of Cretaceous pterodactyloid pterosaurs. In the Jiufotang Formation (Lower Cretaceous, Aptian) of northeastern China, pterodactyloids are represented by azhdarchoids and pteranodontoids, including istiodactylids and anhanguerians. Here, we describe a new pterosaur from this unit that represents a new species of toothed pteranodontoid. Its overall morphology is consistent with other toothed pteranodontoids but shows some interesting features such as the orbit being more ventrally positioned than in all other species from this clade. It differs markedly from all other pterosaurs from this unit, including Liaoningopterus, Guidraco and Ikrandraco, with which the new taxon is possibly related. In addition to the description of the new taxon, we also describe the anhanguerid Liaoningopterus gui in more detail. The new species, Liaoningopterus gui, Guidraco venator and Ikrandraco avatar, are large pterosaurs with very distinct tooth morphologies, suggesting that they had different prey preferences, partially explaining how the Jiufotang Formation could bear such a high diversity of pterosaur species.

Were early pterosaurs inept terrestrial locomotors?

Pterodactyloid pterosaurs are widely interpreted as terrestrially competent, erect-limbed quadrupeds, but the terrestrial capabilities of non-pterodactyloids are largely thought to have been poor. This is commonly justified by the absence of a non-pterodactyloid footprint record, suggestions that the expansive uropatagia common to early pterosaurs would restrict hindlimb motion in walking or running, and the presence of sprawling forelimbs in some species. Here, these arguments are re-visited and mostly found problematic. Restriction of limb mobility is not a problem faced by extant animals with extensive fight membranes, including species which routinely utilise terrestrial locomotion. The absence of non-pterodactyloid footprints is not necessarily tied to functional or biomechanical constraints. As with other fully terrestrial clades with poor ichnological records, biases in behaviour, preservation, sampling and interpretation likely contribute to the deficit of early pterosaur ichnites. Suggestions that non-pterodactyloids have slender, mechanically weak limbs are demonstrably countered by the proportionally long and robust limbs of many Triassic and Jurassic species. Novel assessments of pterosaur forelimb anatomies conflict with notions that all non-pterodactyloids were obligated to sprawling forelimb postures. Sprawling forelimbs seem appropriate for species with ventrally-restricted glenoid articulations (seemingly occurring in rhamphorhynchines and campylognathoidids). However, some early pterosaurs, such as Dimorphodon macronyx and wukongopterids, have glenoid arthrologies which are not ventrally restricted, and their distal humeri resemble those of pterodactyloids. It seems fully erect forelimb stances were possible in these pterosaurs, and may be probable given proposed correlation between pterodactyloid-like distal humeral morphology and forces incurred through erect forelimb postures. Further indications of terrestrial habits include antungual sesamoids, which occur in the manus and pes anatomy of many early pterosaur species, and only occur elsewhere in terrestrial reptiles, possibly developing through frequent interactions of large claws with firm substrates. It is argued that characteristics possibly associated with terrestriality are deeply nested within Pterosauria and not restricted to Pterodactyloidea as previously thought, and that pterodactyloid-like levels of terrestrial competency may have been possible in at least some early pterosaurs.

Pterodactylus scolopaciceps Meyer, 1860 (Pterosauria, Pterodactyloidea) from the Upper Jurassic of Bavaria, Germany: the problem of cryptic pterosaur taxa in early ontogeny.

The taxonomy of the Late Jurassic pterodactyloid pterosaur Pterodactylus scolopaciceps Meyer, 1860 from the Solnhofen Limestone Formation of Bavaria, Germany is reviewed. Its nomenclatural history is long and complex, having been synonymised with both P. kochi (Wagner, 1837), and P. antiquus (Sömmerring, 1812). The majority of pterosaur species from the Solnhofen Limestone, including P. scolopaciceps are represented by juveniles. Consequently, specimens can appear remarkably similar due to juvenile characteristics detracting from taxonomic differences that are exaggerated in later ontogeny. Previous morphological and morphometric analyses have failed to separate species or even genera due to this problem, and as a result many species have been subsumed into a single taxon. A hypodigm for P. scolopaciceps, comprising of the holotype (BSP AS V 29 a/b) and material Broili referred to the taxon is described. P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate. Consequently, the new genus Aerodactylus is erected to accommodate it. Aerodactylus can be diagnosed on account of a unique suite of characters including jaws containing 16 teeth per-jaw, per-side, which are more sparsely distributed caudally and terminate rostral to the nasoantorbital fenestra; dorsal surface of the skull is subtly depressed rostral of the cranial table; rostrum very elongate (RI = ∼7), terminating in a point; orbits correspondingly low and elongate; elongate cervical vertebrae (approximately three times the length of their width); wing-metacarpal elongate, but still shorter than the ulna and first wing-phalanx; and pteroid approximately 65% of the total length of the ulna, straight and extremely thin (less than one third the width of the ulna). A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.

A new toothed pterosaur (Pterodactyloidea: Anhangueridae) from the Early Cretaceous Romualdo Formation, NE Brazil

A new species of pterosaur, Maaradactylus kellneri gen. nov., sp. nov. (Archosauria: Pterosauria) from the Romualdo Formation (Aptian/Albian), is herein described. The specimen (MPSC R 2357) was found at Sítio São Gonçalo, Santana do Cariri city (State of Ceará, northeast Brazil) and consists of the skull, atlas and axis, and represents one of the largest skulls of the Anhangueridae from the Araripe Basin described. The autapomorphies of the new pterosaur include the following characters: a premaxillary sagittal crest that is relatively long and high, beginning at the anterior part of the skull (rostrum) and extending to the 22nd pair of alveoli, not covering the nasoantorbital fenestra or the choanaes, and also the presence of 35 pairs of alveoli; smooth palatal ridge, which starts on the 5th pair of alveoli and ends on the 13th pair; palate is convex shaped in the anterior region; choanae not extending laterally; small and convex palatal elevation; the 5th, 6th and 7th alveoli smaller than the 4th and 8th; the alveoli decreasing in size from the 9th to the 12th and increasing from the 13th to 18th, and from the 18th to the 35th they are arranged in triplets. Furthermore, the lateral surface of the premaxillary crest shows grooves and tridimensional structures that may have housed blood vessels.

The first pterosaur 3-D egg: Implications for Pterodaustro guinazui nesting strategies, an Albian filter feeder pterosaur from central Argentina

The increasing number of fossil pterosaur eggs sheds light on nesting environments and breeding behaviors of these extinct flying reptiles. Here we report the first partial three-dimensional egg of the pterosaur, Pterodaustro guinazui, from central Argentina. The specimen was discovered from the same Albian deposits as the exceptional P. guinazui embryo described in 2004. Microscopic characterizations indicate a pristine preservation of the 50 μm thick calcium carbonate, which differs significantly from the soft shell of Chinese pterosaur eggs. Estimate of the eggshell conductance implies that the nest had a minimum moisture content of 75%. This moisture estimate, combined with geological and taphonomical data, suggests that P. guinazui may have adopted a nesting strategy similar to those of grebes and flamingos rather than being buried on land, as previously hypothesized. Moreover, our results demonstrate that the nesting paleoenvironment of this pterosaur species was closely linked to a mesohaline lacustrine ecosystem in a basin governed by regional tectonic subsidence, a setting characteristic for the feeding and reproduction of modern flamingos.

Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs from China

The pterosaur record is generally poor, with little information about their populations, and pterosaur eggs are even rarer, with only four isolated and flattened eggs found to date. We report here a population of a new sexually dimorphic pterosaur species (Hamipterus tianshanensis gen. et sp. nov.), with five exceptionally well-preserved three-dimensional eggs, from the Early Cretaceous deposit in northwestern China. About 40 male and female individuals in total were recovered, but the actual number associated might be in the hundreds. All of the discovered skulls have crests, which exhibit two different morphologies in size, shape, and robustness. The eggs show pliable depressions with cracking and crazing on the outer surface. The eggshell, observed by scanning electron microscopy and energy-dispersive spectroscopy, comprises a thin calcareous external hard shell followed by a soft membrane. These fossils shed new light on the reproductive strategy, ontogeny, and behavior of pterosaurs. The cranial crests show sexually dimorphic morphologies, with presumed males and females differing in crest size, shape, and robustness. Ontogenetic variation is reflected mainly in the expansion of the rostrum. The eggs have some external rigidity of the general pliable eggshell, and the microstructure of the eggshell is similar to that of some modern "soft" snake eggs. We suggest that this new pterosaur nested in colonies and thus exhibited gregarious behavior, a possible general trend for at least derived pterodactyloid pterosaurs.

Pterosaurs: natural history, evolution, anatomy

For 150 million years, the skies didn't belong to birds--they belonged to the pterosaurs. These flying reptiles, which include the pterodactyls, shared the world with the nonavian dinosaurs until their extinction 65 million years ago. Some pterosaurs, such as the giant azhdarchids, were the largest flying animals of all time, with wingspans exceeding thirty feet and standing heights comparable to modern giraffes. This richly illustrated book takes an unprecedented look at these astonishing creatures, presenting the latest findings on their anatomy, ecology, and extinction. Pterosaurs features some 200 stunning illustrations, including original paintings by Mark Witton and photos of rarely seen fossils. After decades of mystery, paleontologists have finally begun to understand how pterosaurs are related to other reptiles, how they functioned as living animals, and, despite dwarfing all other flying animals, how they managed to become airborne. Here you can explore the fossil evidence of pterosaur behavior and ecology, learn about the skeletal and soft-tissue anatomy of pterosaurs, and consider the newest theories about their cryptic origins. This one-of-a-kind book covers the discovery history, paleobiogeography, anatomy, and behaviors of more than 130 species of pterosaur, and also discusses their demise at the end of the Mesozoic. The most comprehensive book on pterosaurs ever published Features some 200 illustrations, including original paintings by the author Covers every known species and major group of pterosaurs Describes pterosaur anatomy, ecology, behaviors, diversity, and more Encourages further study with 500 references to primary pterosaur literature Some images inside the book are unavailable due to digital copyright restrictions.

The Early Evolutionary History and Adaptive Radiation of the Pterosauria

Abstract:Phylogenetic analyses of early pterosaur species are relatively new and contradictory. However, they imply a similar evolutionary history for early pterosaurs: a large divergence of all major early groups of pterosaurs before the first named pterosaur species appeared in the fossil record. This large, unsampled divergence may be a record of the initial adaptive radiation of the pterosaurs, but a recent comprehensive phylogenetic analysis reconstructs named Triassic pterosaur species grouped together in a monophyletic clade with all other major groups diverging later. Ten patterns that characterize adaptive radiations put forward by Gavrilets and Losos (2009) are assessed for congruence with the comprehensive phylogeny and two previous phylogenies to determine which are consistent with our notions of an adaptive radiation. Of the eight patterns that can be applied to pterosaurs, only six vary between pterosaur phylogenies. Of these six patterns, all apply to the three phylogenies with varying amounts of support For many patterns, however, the comprehensive phylogeny has a greater magnitude, shorter time span, or is the only topology within which they can be assessed. Pterosaurs are characterized by an adaptive radiation no matter which phylogeny is considered, but congruence with the fossil record increases the support and information content of a phylogeny by reducing the time and area within which to reconstruct evolutionary history.

Integration and dissociation of limb elements in flying vertebrates: a comparison of pterosaurs, birds and bats

Flapping flight has evolved independently in three vertebrate clades: pterosaurs, birds and bats. Each clade has a unique flight mechanism involving different elements of the forelimb. Here, patterns of limb integration are examined using partial correlation analysis within species and matrix correlation analysis across species to test whether the evolution of flapping flight has involved developmental dissociation of the serial homologues in the fore- and hind limb in each clade. Our sample included seven species of birds, six species of bats, and three species of pterosaurs for which sufficient sample sizes were available. Our results showed that, in contrast to results previously reported for quadrupedal mammals, none of the three clades demonstrated significant integration between serial homologues in the fore- and hind limb. Unexpectedly, there were few consistent patterns of within-forelimb correlations across each clade, suggesting that wing integration is not strongly constrained by functional relationships. However, there was significant integration within the hind limbs of pterosaurs and birds, but not bats, possibly reflecting the differing functions of hind limbs (e.g. upright support vs. suspension) in these clades.

NEW PTEROSAUR SPECIMENS FROM THE KEM KEM BEDS (UPPER CRETACEOUS, CENOMANIAN) OF MOROCCO

Although pterosaurs from Africa are still rare, in recent years several specimens have been described from the Kem Kem beds (Upper Cretaceous, Cenomanian) of Morocco. Here we describe four additional specimens from this informal lithostratigraphic unit: a jaw fragment, two mid-cervical vertebrae, and a humerus. All these specimens show three-dimensional preservation, differing much from the flat condition found in most pterosaur material. The vertebrae are particularly well preserved, and allow accurate observations on the pneumatization of the neural arch. Based on comparable material, we show that at least two edentulous pterosaur species were present in this informal lithostratigraphic unit, thus adding to the growing evidence of considerable pterosaur diversity in northwestern Africa during the middle Cretaceous. So far, the Kem Kem beds have the most diverse pterosaur fauna in this continent, with the presence of anhanguerids, azhdarchids, pteranodontids, and tapejarids.

Vertebrate diversity of the Jehol Biota as compared with other lagerstätten

In the last twenty years, the extraordinary discoveries of vertebrate fossils from the Jehol Biota not only have important implications for studying the evolution of major Mesozoic vertebrate groups, their paleobiostratigraphy and paleoenvironmentology, but also provide critical evidence for understanding the biodiversity changes of the Early Cretaceous ecosystem. Currently, the Jehol Biota in a narrow sense (i.e., distribution limited to western Liaoning, northern Hebei, and southeastern Inner Mongolia) comprises a vertebrate assemblage of at least 121 genera and 142 species. Among them are 13 genera and 15 species of mammals, 33 genera and 39 species of birds, 30 genera and 35 species of dinosaurs, 17 genera and species of pterosaurs, 5 genera and species of squamates, 5 genera and 7 species of choristoderes, 2 genera and species of turtles, 8 genera and species of amphibians, 7 genera and 13 species of fishes as well as 1 genus and species of agnathan. All these known 121 genera are extinct forms, and only a small percentage of them (e.g., agnathans, some fishes and amphibians) can be referred to extant families. The Jehol vertebrate diversity already exceeds that of the contemporaneous lagerstatten such as Santana Fauna from Brazil and the Las Hoyas Fauna from Spain, and is nearly as great as that of the Jurassic Solnhofen Fauna and the Eocene Messel Fauna from Germany. Therefore, The Jehol Biota undoubtedly represents a world class lagerstatte in terms of both fossil preservation and vertebrate diversity. The success of the Jehol vertebrate diversity had a complex biological, geological, and paleoenvironmental background. Analysis of the habitat and diet of various vertebrate groups also indicates that the habitat and dietary differentiation had played a key role in the success of the taxonomic diversity of vertebrates of various ranks. Furthermore, the interactions among vertebrates, plants, and invertebrates as well as the competitions among various vertebrate groups and some key morphological innovations also contributed to the success of the Jehol vertebrate diversity.