Genus of lonchodraconid pterosaur from the Cretaceous period
Lonchodraco
is a
genus
of
lonchodraconid
pterodactyloid
pterosaur
from the Late
Cretaceous
of southern
England
. The genus includes species that were previously assigned to other genera.
[1]
Discovery and naming
[
edit
]
In 1846,
James Scott Bowerbank
named and described some remains found in a chalk pit at
Burham
near
Maidstone
in
Kent
, as a new species of
Pterodactylus
:
Pterodactylus giganteus
. The
specific name
means "the gigantic one" in
Latin
.
[2]
The same pit generated remains of
Pterodactylus cuvieri
.
[3]
In 1848, Bowerbank published a
histological
study of the bone structure of
P. giganteus
.
[4]
At the time, the
British Association Code
of 1843 allowed to change names if they were inappropriate. In 1850,
Richard Owen
, considering the species not to have been particularly large, and renamed it into
Pterodactylus conirostris
; the specific name meaning "cone-snouted", which was based on the conical snout of specimen NHMUK PV 39412.
[5]
However, after insistent objections by Bowerbank, Owen retracted this name in 1851 when he described the finds in more detail.
[6]
In 1914
Reginald Walter Hooley
assigned the species to a new genus
Lonchodectes
, "the lance biter", as a
Lonchodectes giganteus
.
[7]
In 2013,
Taissa Rodrigues
and
Alexander Wilhelm Armin Kellner
concluded that the
type species
of
Lonchodectes
,
Lonchodectes compressirostris
, was a
nomen dubium
. Therefore, they created a new genus
Lonchodraco
, combining Greek λ?γχη,
lonch?
, "lance", with Latin
draco
, "dragon".
Pterodactylus giganteus
was made the type species of
Lonchodraco
, resulting in a
Lonchodraco giganteus
. Two other species previously assigned to
Lonchodectes
were moved to the new genus, resulting in a
Lonchodraco machaerorhynchus
and a
Lonchodraco(?) microdon
. The question mark in the latter name indicates that the authors were uncertain about the correctness of the assignment.
[1]
Rodrigues and Kellner considered
NHMUK PV 39412
to be the
lectotype
of
Lonchodraco giganteus
, after a choice by
Peter Wellnhofer
in 1978.
[8]
It was found in a layer of the
Chalk Formation
, dating from the
Cenomanian
-
Turonian
. It consists of the front of a snout, the front of a pair of lower jaws, a piece of a
scapulocoracoid
, the upper parts of a humerus and an ulna, and a part of a wing finger phalanx.
[1]
Also in 1869, Seeley informally named "Ptenodactylus microdon".
[9]
In 1870, he formally named it
Ornithocheirus microdon
, "small tooth",
[10]
Hooley (1914) transferred this species to
Lonchodectes
to form the new combination
Lonchodectes microdon
.
[7]
Its holotype, CAMSM B54486, has its provenance in the Cambridge Greensand and consists of the front of a snout. The type specimen of
Ornithocheirus oweni
Seeley 1870, CAMSM B 54439, was synonymized with
microdon
by Unwin (2001),
[11]
and Rodrigues & Kellner (2013) agreed with this synonymy.
[1]
In 1869,
Harry Govier Seeley
named
Ptenodactylus machaerorhynchus
,
[9]
at the same time disclaiming the name which makes it invalid by modern standards. In 1870, Seeley had realised that the generic name
Ptenodactylus
had been preoccupied and renamed the species into
Ornithocheirus
machaerorhynchus
.
[10]
The specific name means "sabre snout" in Greek. In 1914 Hooley renamed it into
Lonchodectes machae[r]orhynchus
.
[7]
Its holotype, CAMSM B54855, was near
Cambridge
found in a layer of the
Cambridge Greensand
dating from the Cenomanian but containing reworked fossils from the
Albian
. It consists of the rear end of a
symphysis
of the lower jaws.
[1]
However, in his review of Lonchodectidae, Averianov (2020) assigned
Lonchodraco machaerorhynchus
to
Ikrandraco
due to similarities in rostral morphology, as
I. machaerorhynchus
, and he also declared
Lonchodraco microdon
(including
P. oweni
) a junior synonym of
machaerorhynchus
. Thus,
Lonchodraco
is limited to the type species
L. giganteus
.
[12]
Description
[
edit
]
Rodrigues & Kellner treated
Lonchodraco
as a
clade
, which thus could possess
synapomorphies
, shared derived traits, setting the clade apart from related groups. They established one of these: the tooth sockets are elevated relative to the palate and lower jaw edge. Also a unique combination of themselves not unique traits was present. The tooth sockets in the front of the jaws are small, with a diameter of no more than four millimetres. These sockets do not vary significantly in size. The distance between the tooth sockets about equals their diameter. The midline ridge on the palate is high. A crest is present below the lower jaws.
[1]
Bowerbank estimated
P. giganteus
had a
wingspan
of about eight to nine feet. Rodrigues & Kellner established two autapomorphies of
Lonchodraco giganteus
. Below the front of the lower jaws a short blade-like crest is present. There is a density of about six tooth sockets per three centimetres of jaw edge. There is a unique combination of traits: the snout bears a crest; the front part of the snout is rounded; the front part of the lower jaws is rounded; the margins of the front tooth sockets diverge.
[1]
Classification
[
edit
]
In 2013, Brazilian paleontologists Rodrigues & Kellner assigned
Lonchodraco
to a family called
Lonchodraconidae
, which was not defined as a clade and of which
Lonchodraco
was the only member. Later in their analysis however, Rodrigues & Kellner considered the definition of Lonchodraconidae to be more or less synonymous to that of
Lonchodectidae
, however, they stated that
Lonchodectes
is a
nomen dubium
and therefore should not be included in the group. In their
cladistic
analysis, they concluded that the three species of
Lonchodraco
formed a cluster, but it proved impossible to obtain a precise position for it because their inclusion in the dataset made the tree largely collapse into a
polytomy
containing, apart from the three species, all Pterodactyloidea and even the
Rhamphorhynchidae
.
[1]
A topology recovered by Longrich and colleagues in 2018 placed
Lonchodraco
within the family Lonchodectidae as the sister taxon of
Lonchodectes
, with the family being placed within the larger group
Ornithocheiromorpha
.
[13]
However, in several recent studies, including Pegas
et al.
(2019) and Holgado & Pegas (2020), the term Lonchodraconidae is used, and
Lonchodraco
is recovered within this group, sister taxon to
Ikrandraco
.
[14]
[15]
Topology 1
: Longrich
et al.
(2018).
|
Topology 2
: Pegas
et al.
(2019).
|
See also
[
edit
]
References
[
edit
]
- ^
a
b
c
d
e
f
g
h
Rodrigues, T.; Kellner, A. (2013).
"Taxonomic review of the
Ornithocheirus
complex (Pterosauria) from the Cretaceous of England"
.
ZooKeys
(308): 1?112.
Bibcode
:
2013ZooK..308....1R
.
doi
:
10.3897/zookeys.308.5559
.
PMC
3689139
.
PMID
23794925
.
- ^
Bowerbank, J.S. (1846).
"On a new species of pterodactyl found in the Upper Chalk of Kent (
Pterodactylus giganteus
)"
.
Quarterly Journal of the Geological Society of London
.
2
: 7?9.
doi
:
10.1144/gsl.jgs.1846.002.01-02.05
.
S2CID
129389179
.
- ^
Bowerbank, J.S. (1851).
"On the pterodactyles of the Chalk Formation"
.
Proceedings of the Zoological Society of London
.
19
: 14?20.
doi
:
10.1111/j.1096-3642.1851.tb01125.x
.
- ^
Bowerbank, J.S. (1848).
"Microscopical observations on the structure of the bones of
Pterodactylus giganteus
and other fossil animals"
.
Quarterly Journal of the Geological Society
.
4
(1?2): 2?10.
doi
:
10.1144/gsl.jgs.1848.004.01-02.07
.
S2CID
131742710
.
- ^
Dixon, F., 1850
The geology and fossils of the Tertiary and Cretaceous Formations of Sussex
. Longman, Brown, Green, and Longmans, London, 423 pp
- ^
Owen, R., 1851,
A monograph on the fossil Reptilia of the Cretaceous formations
. Palaeontographical Society, London, 118 pp
- ^
a
b
c
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
.
13
(78): 529?557.
doi
:
10.1080/00222931408693521
.
- ^
Wellnhofer, P., 1978,
Pterosauria. Handbuch der Palaoherpetologie, Teil 19
. Gustav Fischer Verlag, Stuttgart and New York, 82 pp
- ^
a
b
Seeley, H.G., 1869,
Index to the fossil remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata arranged in the Woodwardian Museum of the University of Cambridge
. Deighton, Bell and Co., Cambridge, xxiii + 143 pp
- ^
a
b
Seeley, H.G., 1870,
The Ornithosauria: an elementary study of the bones of pterodactyls, made from fossil remains found in the Cambridge Upper Greensand, and arranged in the Woodwardian Museum of the University of Cambridge
. Deighton, Bell, and Co., Cambridge, xii + 135 pp
- ^
Unwin, D.M. (2001). "An overview of the pterosaur assemblage from the Cambridge Greensand (Cretaceous) of Eastern England".
Mitteilungen aus dem Museum fur Naturkunde in Berlin, Geowissenschaftliche Reihe
.
4
: 189?221.
doi
:
10.1002/mmng.4860040112
.
- ^
Averianov, A.O. (2020).
"Taxonomy of the Lonchodectidae (Pterosauria, Pterodactyloidea)"
.
Proceedings of the Zoological Institute RAS
.
324
(1): 41?55.
doi
:
10.31610/trudyzin/2020.324.1.41
.
- ^
Longrich, N.R., Martill, D.M., and Andres, B. (2018).
"Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary."
PLoS Biology
,
16
(3): e2001663.
doi
:
10.1371/journal.pbio.2001663
- ^
Rodrigo V. Pegas, Borja Holgado & Maria Eduarda C. Leal (2019) On
Targaryendraco wiedenrothi
gen. nov. (Pterodactyloidea, Pteranodontoidea, Lanceodontia) and recognition of a new cosmopolitan lineage of Cretaceous toothed pterodactyloids, Historical Biology,
doi
:
10.1080/08912963.2019.1690482
- ^
Holgado, B.; Pegas, R.V. (2020).
"A taxonomic and phylogenetic review of the anhanguerid pterosaur group Coloborhynchinae and the new clade Tropeognathinae"
.
Acta Palaeontologica Polonica
.
65
.
doi
:
10.4202/app.00751.2020
.