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Genus of chaoyangopterid pterosaur from the Early Cretaceous
Eoazhdarcho
is a
genus
of
azhdarchoid
pterodactyloid
pterosaur
named in
2005
by Chinese
paleontologists
Lu Junchang
and
Ji Qiang
. The
type and only known species
is
Eoazhdarcho liaoxiensis
. The
fossil
was found in the
Aptian
-age
Lower Cretaceous
Jiufotang Formation
of
Chaoyang
,
Liaoning
,
China
.
Etymology
[
edit
]
The genus name,
Eoazhdarcho
, combines a Greek
eos
, "dawn" with the name of the genus
Azhdarcho
, with the implication it was an early related form of the latter. The
specific name
,
liaoxiensis
, refers to the ancient region
Liaoxi
.
[1]
Description
[
edit
]
Eoazhdarcho
is based on
holotype
GMN-03-11-02, a partial skeleton and lower jaw, and is distinguished from other pterosaurs by the proportions of its bones. The metacarpals are very elongated but the cervical vertebrae and hind limbs are not. It was relatively small by azhdarchoid standards, with a
wingspan
of about 1.6 meters (5.2 feet).
[1]
Classification
[
edit
]
The describers first assigned
Eoazhdarcho
to the
Azhdarchidae
in a
basal
position, and compared it to
Azhdarcho
.
[1]
However, in 2006 they published a
cladistic
analysis, determining that several forms, among them
Eoazhdarcho
, were united in a natural group, a separate
clade
that could be set apart from an Azhdarchidae proper.
[2]
In 2008 that clade was by Lu, Unwin and colleagues named the
Chaoyangopteridae
? the sister group of the Azhdarchidae within a much larger
Azhdarchoidea
? with
Eoazhdarcho
as one of the members.
[3]
In 2014, a
phylogenetic analysis
conducted by Brian Andres and colleagues had recovered
Eoazhdarcho
as the
basalmost
member of the family
Chaoyangopteridae
, sister taxon to the subfamily Chaoyangopterinae. The
cladogram
of their analysis is presented on the left.
[4]
Later, in 2018, a
phylogenetic analysis
conducted by paleontologist Nicholas Longrich and colleagues had recovered
Eoazhdarcho
in a different position within the
Neoazhdarchia
, as a basal member of the clade
Neopterodactyloidea
.
[5]
The cladogram of their analysis is presented on the right:
Topology 1
: Andres
et al.
(2014).
|
Topology 2
: Longrich
et al.
(2018).
|
See also
[
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]
References
[
edit
]
- ^
a
b
c
Lu, Junchang; Qiang Ji (2005). "New azhdarchid pterosaur from the Early Cretaceous of western Liaoning".
Acta Geologica Sinica
.
79
(3): 301?307.
doi
:
10.1111/j.1755-6724.2005.tb00893.x
.
S2CID
128958556
.
- ^
Lu, Junchang; Qiang Ji (2006).
"Preliminary results of a phylogenetic analysis of the pterosaurs from western Liaoning and surrounding area"
(PDF)
.
Journal of the Paleontological Society of Korea
.
22
(1): 239?261
. Retrieved
2007-03-10
.
- ^
Lu, J., Unwin, D.M., Xu, L., and Zhang, X. (2008). "A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution."
Naturwissenschaften
,
95
: 891?897
- ^
Andres, B.; Clark, J.; Xu, X. (2014).
"The Earliest Pterodactyloid and the Origin of the Group"
.
Current Biology
.
24
(9): 1011?6.
doi
:
10.1016/j.cub.2014.03.030
.
PMID
24768054
.
- ^
Longrich, Nicholas R.; Martill, David M.; Andres, Brian; Penny, David (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
.
PMC
5849296
.
PMID
29534059
.
External links
[
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]