Wann Langston’s research while affiliated with University of Texas at Austin and other places

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Publications (3)


Functional morphology of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)
  • Article
  • Full-text available

December 2021

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134 Reads

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11 Citations

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James R. Cunningham

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Wann Langston

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John Conway

We reconstruct the proportions and possible motions of the skeleton of the giant azhdarchid pterosaur Quetzalcoatlus. The neck had substantial dorsoventral mobility, and the head and the neck could swing left and right through an arc of ca. 180°. In flight, it is most plausible that the hind limbs were drawn up bird-like, with the knee anterior to the acetabulum. In this position, an attachment of the wing membrane to the hind limb would have been useless. A straight-legged posterior extension of the hind limb, such as rotation of the hind limb into a fully ‘bat-like’ pose, was likely prevented by soft tissues of the hip joint. Given these difficulties, the traditional ‘broad-winged’ bat-like restoration is unrealistic. On the ground, Quetzalcoatlus, like other ornithodirans, had an erect stance and a parasagittal gait. Terrestrial locomotion was powered almost entirely by the hind limbs. The pace length would have been limited to the length of the glenoacetabular distance, except that Quetzalcoatlus (like other pterodactyloids) had a unique gait in which the forelimb was elevated out of the way of the hind limb from step to step. If the humerus were retracted 80° and adducted nearly to the body wall, the elbow and wrist may have been able to extend to effect a quadrupedal launch with assistance from the hind limbs, assuming sufficient long bone strength and sufficient extensor musculature at these forelimb joints. A bipedal launch using the hind limbs alone also appears plausible: despite the animal’s great size, the hind limb to torso length ratio is the greatest for all known pterosaurs.

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Morphology and taxonomy of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)

December 2021

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900 Reads

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35 Citations

Quetzalcoatlus is the largest flying organism ever known and one of the most familiar pterosaurs to the public. Despite a half century of interest, it remains very incompletely described. This shortfall is addressed here through a full morphological description of Quetzalcoatlus and the other pterosaur material of Big Bend National Park, Texas. The first reported material was described and named Quetzalcoatlus northropi by Douglas Lawson in 1975, but in two separate publications. A ruling by the International Commission of Zoological Nomenclature was required for the name to be made available. Review of the pterosaur fauna of the Park recovers three valid species of azhdarchid pterosaurs in the latest Cretaceous Period Javelina and Black Peaks formations. The size and occurrence of these species are correlated with depositional environment. The holotype of the giant Quetzalcoatlus northropi and six other giant specimens referred to it occur in stream-channel deposits, including the youngest reported pterosaur. The vast majority of specimens (200+) are from large pterosaurs found in the abandoned channel-lake deposits at Pterodactyl Ridge; they form a diagnosable natural group erected as the new species Quetzalcoatlus lawsoni. A moderate-sized partial skull and cervical series also found in the abandoned channel-lake deposits at Pterodactyl Ridge, but lower in the section, is distinct from both species and is erected as Wellnhopterus brevirostris, gen. et sp. nov. Overbank flood-plain facies preserve another eleven specimens of extreme size variation, including small azhdarchids. The Big Bend pterosaur fauna provides the greatest known sample of azhdarchid pterosaurs and three-dimensional pterosaur morphology.


FIGURE 1. Map showing location of International Telephone and Telegraph (I.T.T.) measured section ("Selmer Crab Site") and the associated stratigraphic column of the upper Coon Creek Formation. Green areas in McNairy County map show areal extent of Coon Creek Formation. Gray areas in Selmer inset represent municipal limits, I.T.T measured section indicated by red star. Pterosaur fossil occurs in the lower part of subunit 3 (indicated by arrow), a thinly laminated micaceous silty clay capped by large ironstone concretions.
FIGURE 2. Photograph of the I.T.T. exposure. The pterosaur-bearing subunit 3 dark shales are in the foreground separated from the overlying subunit 4 at the thin tree line in the middle of the photograph. This tree line also marks the position of the ironstone concretion layer. Location of MPPM 2000.23.1 indicated by white arrow.
FIGURE 3. Articulated crab carapace from subunit 3 of the I.T.T. section. The dark fine-grained nature of the sediment along with the abundance of articulated crabs, snail steinkerns, fish spines and teeth indicate a quiet water marine environment of deposition.
FIGURE 5. Reconstruction of MPPM 2000.23.1 in dorsal view. Gray areas represent materials present. Orientation and placement of the long piece of the centrum are conjectural. There is no contact between these fragments, so the reconstruction represents the minimum length of the vertebra.
A cervical vertebra of Arambourgiania philadelphiae (Pterosauria, Azhdarchidae) from the late Campanian micaceous facies of the Coon Creek Formation in McNairy County, Tennessee, USA

December 2016

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624 Reads

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6 Citations

Late Cretaceous azhdarchid pterosaurs are known from fairly incomplete remains in North America. These remains have primarily been reported from continental and fluvial deposits of the western United States. Here we refer a fragmentary cervical vertebra from the Late Campanian micaceous facies of the Coon Creek Formation of Tennessee, a near-shore marine deposit, to the azhdarchid pterosaur taxon Arambourgiania philadelphiae. This specimen represents the first reported occurrence of A. philadelphiae from North America, expands the temporal range of A.philadelphiae from the Maastrichtian to the Late Campanian, is the first reported occurrence of Pterosauria from the state of Tennessee, and extends the known geographic range of the Azhdarchidae to the eastern Gulf Coastal Plain of the United States.

Citations (3)


... The skull is represented by the upper and lower jaws, preserved anterior to the nasoantorbital fenestra (Fig. 4). Based on rostral proportions in other edentulous pterosaurs (e.g., Quetzalcoatlus, Andres & Langston, 2021), this represents at least 80% of the skull length. We identify the upper jaw by the presence of the ventral margin of the nasoantorbital fenestra preserved on the left side; the lower jaw is identified by the presence of the symphysis and mandibular rami. ...

Reference:

New pterosaur remains from the Late Cretaceous of Afro-Arabia provide insight into flight capacity of large pterosaurs
Morphology and taxonomy of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)

... 15,16 However, attempts to identify the terrestrial capabilities and feeding ecologies of specific clades have created much controversy, 17,18 and the terrestrial abilities of both non-pterodactyliforms 17 and pterodactyliforms are highly debated. [19][20][21] Despite these controversies, pterosaur hand and foot morphologies have been largely overlooked, 14,22,23 with little documentation of how these vary across Pterosauria. This oversight is particularly remarkable considering the fundamental role they play in locomotion. ...

Functional morphology of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)

... TMM 42889-1 is nearly complete, missing only the prezygapophyses (processus articulares craniales of Martill, 1996, or epipophyses of Buffetaut, 2001) and cervical ribs (diminutive ribs and vestigial ribs of Godfrey and Currie, 2005, bridges of bone of Watabe et al., 2009, or vestigial cervical ribs of Vremir et al., 2015 or ventrally directed crests of Harrell et al., 2017). Length measurements have systematic importance for cervical vertebrae, and so it is important to estimate the length of the missing prezygapophyses to get the total length of the vertebra. ...

A cervical vertebra of Arambourgiania philadelphiae (Pterosauria, Azhdarchidae) from the late Campanian micaceous facies of the Coon Creek Formation in McNairy County, Tennessee, USA