Lonchodectes

Lonchodectes Temporal range: Early-Late Cretaceous, 94 Ma PreЄ Є O S D C P T J K Pg N ↓
Holotype jaw fragment of L. compressirostris
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Pterosauria
Suborder:	†Pterodactyloidea
Clade:	†Azhdarchoidea
Family:	†Lonchodectidae Hooley, 1914
Genus:	†Lonchodectes Hooley, 1914
Type species
Pterodactylus compressirostris Owen, 1851
Species
Lonchodectes compressirostris (Owen, 1851)

Lonchodectes (meaning "lance biter") was a genus of lonchodectid pterosaur from several formations dating to the Turonian (Late Cretaceous, though possibly as early as the Valanginian) of England, mostly in the area around Kent. The species belonging to it had been assigned to Ornithocheirus until David Unwin's work of the 1990s and 2000s, and the genus is not universally accepted as distinct.^[1] Several potential species are known; most are based on scrappy remains, and have gone through several other generic assignments. The genus is part of the complex taxonomy issues surrounding Early Cretaceous pterosaurs from Brazil and England, such as Amblydectes, Anhanguera, Coloborhynchus, and Ornithocheirus.

History and species

19th century lithograph of the type specimen

Numerous species have been referred to this genus over time, and only those more widely connected with the genus are included here.

The type species, L. compressirostris, is based on BMNH 39410, a partial upper jaw from the Turonian-age Upper Cretaceous Upper Chalk near Kent. Richard Owen named in 1851 as a species of Pterodactylus;^[2] it was transferred to Ornithocheirus in 1870 by Harry Govier Seeley,^[3] before becoming the type species of Lonchodectes in Reginald Walter Hooley's 1914 review of Ornithocheirus.^[4] Confusingly, this species was also long regarded, incorrectly, as the type species of Ornithocheirus.^[5]

Formerly assigned to Lonchodectes

Holotype of L. compressirostris in place with Pterodactylus as template

Hooley added two other species at this time, both of which had also been originally referred to Pterodactylus, then to Ornithocheirus: L. giganteus, a Cenomanian-age jaw fragment;^[6] and L. daviesii, another jaw fragment, from an Albian-age formation.^[7]

The genus acquired several more former Pterodactylus and Ornithocheirus species in the 1990s-2000s. L. sagittirostris, based on BMNH R1823, a lower jaw fragment from the ?Valanginian-Hauterivian-age Lower Cretaceous Hastings Beds of East Sussex,^[7] and L. platystomus^[3] had been acquired by 2000.^[8] Two additional species based on jaw fragments, both from the Albian-age Cambridge Greensand,^[3] were added by 2003: L. machaerorhynchus and L. microdon,^[9] joining L. compressirostris, L. giganteus, L. platystomus, and L. sagittirostris in his listing of valid species.^[10] However, L. giganteus, L. machaerorhynchus, and L. microdon have since been assigned to a new genus, Lonchodraco, while L. sagittirostris has been removed from Lonchodectes and treated as a nomen dubium at Pterodactyloidea incertae sedis.^[11]

Classification

Holotype jaw of the dubious species L. sagittirostris in multiple views

L. sagittirostris lithograph

The genus is poorly known and not universally accepted, as noted above. In Peter Wellnhofer's 1991 The Illustrated Encyclopedia of Pterosaurs the other major recent synopsis of pterosaurs, written before Unwin's work, the species are included with Ornithocheirus (because of L. compressirostris being thought to be the type species), and are in fact the main fossils illustrated to represent the genus.^[12] Unwin placed them in their own family, Lonchodectidae, which he grouped with the ctenochasmatoids in 2003,^[9] and with the azhdarchoids, including the tapejarids and azhdarchids, in 2006.^[10]

Below is a cladogram showing the phylogenetic placement of this genus within Pteranodontia from Andres and Myers (2013).^[13]

Pteranodontia

Nyctosauridae  Muzquizopteryx coahuilensis "Nyctosaurus" lamegoi Nyctosaurus gracilis Alamodactylus byrdi  Pteranodontoidea  Pteranodon longiceps Pteranodon sternbergi  Istiodactylidae  Longchengpterus zhaoi Nurhachius ignaciobritoi Liaoxipterus brachyognathus Istiodactylus latidens Istiodactylus sinensis Lonchodectes compressirostris Aetodactylus halli Cearadactylus atrox Brasileodactylus araripensis Ludodactylus sibbicki Ornithocheirae  Anhangueridae  Liaoningopterus gui Anhanguera araripensis Anhanguera blittersdorffi Anhanguera piscator Anhanguera santanae  Ornithocheiridae  Tropeognathus mesembrinus Ornithocheirus simus Coloborhynchus clavirostris Coloborhynchus wadleighi

Paleobiology

Lonchodectes attacked by Cimoliopterus

Unwin considers Lonchodectes to have been a generalist, like a seagull, with its conservative jaws and teeth (like those of the much older Pterodactylus) and small to medium size; he estimates its maximum wingspan at about 2 m (6.6 ft). Lonchodectes had long jaws with many short teeth, and the jaws were compressed vertically, like "a pair of sugar tongs with teeth".^[14] At least some of these species had crests on their lower jaws.^[15]

Recent studies, however, show that it had limb proportions akin to those of azhdarchids, and might have lived similarly.^[16][17]

References

1. Kellner, A.W.A. (2003). Pterosaur phylogeny and comments on the evolutionary history of the group: In: Buffetaut, E., and Mazin, J.-M. (Eds.). Evolution and Palaeobiology of Pterosaurs. Geological Society Special Publication 217:105-137. 1-86239-143-2.
2. Owen, R. (1851). Monograph on the fossil Reptilia of the Cretaceous Formations. The Palaeontographical Society 5(11):1-118.
3. Seeley, H.G. (1870). The Ornithosauria: an Elementary Study of the Bones of Pterodactyles. Cambridge, 130 pp.
4. Hooley, R.W. (1914). On the Ornithosaurian genus Ornithocheirus with a review of the specimens from the Cambridge Greensand in the Sedgwick Museum, Cambridge. Annals and Magazine of Natural History, series 8, 78:529-557.
5. Unwin, David M. (2001). "An overview of the pterosaur assemblage from the Cambridge Greensand (Cretaceous) of Eastern England". Mitteilungen as dem Museum für Naturkunde, Berlin, Geowissenschaftliche Reihe 4: 189–222.
6. Bowerbank, J.S. (1846). On a New Species of Pterodactyl. Found in the Upper Chalk of Kent (P. giganteus). Quarterly Journal of the Geological Society 2:7–9.
7. Owen, R. (1874). A Monograph on the Fossil Reptilia of the Mesozoic Formations. 1. Pterosauria. The Palaeontographical Society Monograph 27:1–14.
8. Unwin, D.M., Lü, J., and Bakhurina, N.N. (2000). On the systematic and stratigraphic significance of pterosaurs from the Lower Cretaceous Yixian Formation (Jehol Group) of Liaoning, China. Mitteilungen Museum für Naturkunde der Humboldt-Universität zu Berlin, Geowissenschaftliche Reihe 3:181–206.
9. Unwin, David M. (2003). "On the phylogeny and evolutionary history of pterosaurs". In Buffetaut, Eric; and Mazin, Jean-Michel, (eds.). Evolution and Palaeobiology of Pterosaurs. Geological Society Special Publication 217. London: Geological Society. pp. 139–190. ISBN 1-86239-143-2.
10. Unwin, D.M. (2006). The Pterosaurs: From Deep Time. Pi Press:New York, p. 273. ISBN 0-13-146308-X.
11. Rodrigues, T.; Kellner, A. (2013). "Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England". ZooKeys 308: 1. doi:10.3897/zookeys.308.5559. edit
12. Wellnhofer, Peter (1996) [1991]. The Illustrated Encyclopedia of Pterosaurs. New York: Barnes and Noble Books. pp. 110–113. ISBN 0-7607-0154-7.
13. Andres, B.; Myers, T. S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh: 1. doi:10.1017/S1755691013000303.
14. Unwin, D.M. (2006). The Pterosaurs: From Deep Time. Pi Press:New York, p. 251. ISBN 0-13-146308-X.
15. Unwin, D.M. (2006). The Pterosaurs: From Deep Time. Pi Press:New York, p. 106. ISBN 0-13-146308-X.
16. Unwin, D.M. (2008)
17. Pterosaurs: Natural History, Evolution, Anatomy, Mark P. Witton (2013)

External links

• Re: Pterosaur Help, a posting from George Olshevsky on the Dinosaur Mailing List, which, although incomplete, should give some idea as to the complexity of the taxonomy here. Additional, even more dubious species are included. Accessed 2007-02-10