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Early Cretaceous sauropod and ornithopod trackways from Sichuan + Nova Scotia tetrapods

Ben Creisler

Two recent papers not yet mentioned:

Free pdf:

Lida Xing, Guangzhao Peng, Martin G. Lockley, Yong Ye, Hendrik Klein,
Jianping Zhang and W. Scott Persons IV  (2015)
Early Cretaceous sauropod and ornithopod trackways from a stream
course in Sichuan Basin, Southwest China.
New Mexico Museum of Natural History and Science Bulletin 68: 319–325

The newly discovered dinosaur tracksite in the Lower Cretaceous
Jiaguan Formation of Sichuan Province herein named the Longjing
tracksite reveals at least four diagnostic trackways; three
attributable to sauropods and one to an ornithopod. All trackways
occur on a sandstone bedding plane in a river bed, and consequently
are subject to constant erosion. The individual tracks are rounded to
oval dish shaped impressions (concave epireliefs) that may have been
underprints prior to exhumation and erosion. However the trackway
configurations are clear with the sauropod trackways showing
quadrupedal progression, outward rotation of the pes and typical low
pace angulation ~100°, but poor preservation of manus traces. By
contrast ornithopod trackways represent bipeds with a quadripartite
pes morphology, inward pes rotation and higher pace angulation between
138° and 157°. Ichnotaxonomically, the sauropod trackways cannot be
determined with certainty but are slightly similar to co-eval
specimens from nearby Hanxi and Xinyang tracksites that have been
assigned to cf. Brontopodus. The ornithopod trackway that lacks a
manus imprint is assigned to Caririchnium, a characteristic ichnogenus
from the Early Cretaceous.


Tetrapod assemblages from Fundy rift basin, eastern Canada

Hans-Dieter Sues & Paul Eric Olsen (2015)
Stratigraphic and temporal context and faunal diversity of
Permian-Jurassic continental tetrapod assemblages from the Fundy rift
basin, eastern Canada.
Atlantic Geology 51:  139 - 205
DOI: http://dx.doi.org/10.4138/atlgeol.2015.006

The Fundy basin in Nova Scotia and New Brunswick is the largest
exposed rift basin of the Newark Supergroup and also extends beneath
the Bay of Fundy. Its strata can be divided into four
tectonostratigraphic sequences (TS). TS I is represented by the
probably Permian Honeycomb Point Formation and possibly the Lepreau
Formation. TS II includes the Wolfville Formation with the probably
Middle Triassic Economy Member and the early Late Triassic Evangeline
Member. These members have yielded markedly different assemblages of
continental tetrapods. TS III comprises most of the Blomidon
Formation, which is Norian to Rhaetian in age. The Blomidon Formation
has yielded few skeletal remains of tetrapods to date but many
tetrapod tracks. TS IV includes the late Rhaetian top of the Blomidon
Formation and the McCoy Brook Formation, which overlies the North
Mountain Basalt and is latest Rhaetian and earliest Jurassic
(Hettangian) in age. The McCoy Brook Formation has yielded a diversity
of continental tetrapods and lacks any of the characteristic Late
Triassic forms. Recent work has correlated the Global Boundary
Stratotype Section and Point (GSSP) for the base of the Jurassic
(Hettangian) to a level well above the North Mountain Basalt. Thus
most of the tetrapod fossils from the McCoy Brook Formation are latest
Rhaetian in age, but the higher horizon with skeletal remains of
sauropodomorph dinosaurs may be earliest Hettangian in age. The Fundy
basin preserves the only known, stratigraphically tightly constrained
record of the profound biotic changes in continental ecosystems across
the Triassic-Jurassic transition.