Sorry about missing the week in review last week-there
wasn’t much going on in the world of paleontology. However, the press this week
has brought to my attention some amazing fossil finds.
First we’ve got a beautiful discovery of a pterosaur rookery
in Xinjiang by Dr. Wang Xiaolin. This week his team
released their paper on the discovery, naming the new species Hamipterus
tianshanensis. The sheer amount of
fossil bones reveals much-needed, often-sought but seldom-found information on
the animal. Not only are there 5 intact eggs, but at least 40 individuals. This
number provides information on physical characteristics (the animals are
sexually dimorphic in terms of their crest shape), life cycle (pterosaurs are
found in almost all stages of growth), and social organization (nests are
preserved, and the sheer amount of nests
and individuals suggests a colony not unlike one of seabirds).
It’s been suggested for decades that pterosaurs were social
animals living like birds in large groups, but this time we have an actual
flock. Wang et al classify it as a
relative of the famous Pteranodon, one of the earliest members of the family. Found it the Aptian Cretaceous Turpan-Hami
Basin, it was the successor of the more basal pterosaur Dsungaripterus, but was
more of a generalist fisher.
Speaking of mass finds, there was a mass find of early
Cretaceous Icthyosaurs in Chile. 36 individuals, some of them pregnant, from 4
different species, were found in a single bed at the Torres del Paine National
Park. The find was discovered ten years
ago, but only now has the significance and sheer scope been found. Sadly, the paper
is not available in a free journal, so precise details are not known to me.
However, like the pterosaurs, this suggests a catastrophe, possible a tsunami
or volcanic eruption that killed the animals.
A new short-snouted crocodilian was found in the Paleocene
Cerrejon formation in Colombia by Alexander K. Hastings of the Florida Museum
of Natural History, Jonathan I. Bloch of the Geiseltalmuseum of the Martin
Luther Universität Halle-Wittenberg, and Carlos A. Amarillo of Smithsonian
Tropical Research Institute. Called Anthracosuchus balrogus, it was distinct
for it thick, squared scutes that protected its back, bony tuberosities around
its eyes, wide-spaced eyes, short, broad snout, and rounded, blunt teeth.
Anthracosuchus is a dyrosaur, a family of crocodilians that evolved in the
Palaeocene, flourished, then went extinct. The family was better adapted for
aquatic lifestyles than their modern counterparts, thriving in the jungles and
wetlands of the Palaeogene and eating fish and other aquatic reptiles. The
teeth of this animal seem to be adapted for crushing turtle shells.
At 16-feet long Anthracosuchus dwarfed most of the other
animals of the Cerrejon jungle, including its main prey, the 6-foot turtle
Carbonemys, and its relatives the small but similarly short-snouted
Cerrejonisuchus and common, long-snouted Acherontisuchus. However, it in turn
was prey for the largest snake of all-time, the similarly semiaquatic
Titanoboa. Titanoboa was twice the length of a modern green anaconda, and
fulfilled a similar role as aquatic apex predator.
On to dinosaurs-
Hai Xing and his team from multiple institutions in China,
Canada, and the UK released their paper this week on a new hadrosaur from Henan,
Zhanghenglong yangchengensis. The
animal is described as basal, similar to Bactrosaurus, Telmatosaurus, Lophorhothon, and other ancestors of
hadrosaurs. The find is scanty and
disarticulated, but enough of the skull and post-cranial material remain to get
a good picture of this browser, it’s evolutionary relationships, and it’s
ecological role. It’s placed as a sister
taxon to Nanyangosaurus.
It’s from the Majiacun Formation, a Santonian age
mid-Cretaceous strata discovered relatively recently and with very few fossils.
So far, we know that the troodont Xixiasaurus and alverezasaur Xixianykus shared the habitat, and eggs have
been found suggesting therizinosaurs also lived in the area. Hopefully, more of this animal will be found
and more animals in this environment will be found.
Finally, another
dinosaur was found, this one from Luxembourg and described by Dominique Delsate
from the Musée national d’histoire naturelle de Luxembourg
and Martin D. Ezcurra of the Universities of Birmingham and Munich. It’s a theropod dinosaur from the Hettangian Early Jurassic: a
relative of Megapnosaurus and Sarcosaurus.
The material is scanty-teeth and a foot bone.
The locale, Reckingerwald
quarry, is not known for dinosaurs, either-most of the fossils are of marine invertebrates,
with a few plesiosaur, ichthyosaur, and cartilaginous fish bones. It’s the least of the discoveries in terms of
material and drama, and the dinosaur has yet to be named, but it’s still a find
worth the publicity
Tune in next week
for more paleontology news!