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Ornithopod tracks from Cretaceous of China +.Cubiculum, dino-bone eater + Carboniferous tracks from Morocco



Ben Creisler
bcreisler@gmail.com


Some recent papers in the new issue of Ichnos:

Small ornithopod tracks from Sichuan

Lida Xing & Martin G. Lockley (2014)
First Report of Small Ornithopodichnus Trackways from the Lower
Cretaceous of Sichuan, China.
Ichnos 21(4): 213-222
DOI:10.1080/10420940.2014.951998
http://www.tandfonline.com/doi/full/10.1080/10420940.2014.951998#.VF-oefnF_To

Trackways of ornithopods are well-known from the Lower Cretaceous of
East Asia, particularly in Korea and China. However, most morphotypes
have been identified as Caririchnium which is characterized by
moderate mesaxony, the ratio length = width, or length > width and, in
some cases, by a quadrupedal gait. In 2009 the ichnogenus
Ornithopodichnus, which exhibits distinctively weak mesaxony and a
broader, transverse pes imprint with the ratio length < width, was
identified in Korea, on the basis of material with suboptimal
preservation. The trackmaker was a large ornithopod. Subsequently, in
2009 a second report recognized Ornithopodichnus in China, the
trackmaker being a moderately large quadruped. In 2012,
Ornithopodichnus was described on the basis of well-preserved material
from the Upper Cretaceous of Korea, in this case left by a small,
gregarious biped. Herein we document, a fourth occurrence of
Ornithopodichnus in the Lower Cretaceous Feitianshan Formation of
Sichuan, China which is a further example of trackways that can be
attributed to small, bipedal and gregarious ornithopods. Morphology,
size, trackway pattern and speed of locomotion correspond well with
trackways known from the Korean Hwasun tracksite. Possibly, the
occurrence of Ornithopodichnus which is restricted to East Asia thus
far, is related to ecological and biogeographical pecularities in this
area.

==

Dinosaur-bone-eating carrion insect

Cecilia A. Pirrone, Luis A. Buatois & Bernardo González Riga (2014)
A New Ichnospecies of Cubiculum from Upper Cretaceous Dinosaur Bones
in Western Argentina.
Ichnos 21(4): 251-260
DOI:10.1080/10420940.2014.958225
http://www.tandfonline.com/doi/full/10.1080/10420940.2014.958225#.VF-ou_nF_To


The new ichnospecies Cubiculum levis is described as a bowl-shaped
bioerosion trace fossil in dinosaur bone from the Upper Cretaceous of
western Argentina. The systematic description is based on specific
ichnotaxobases for bioerosion trace fossils in bones. The main
characteristics of the new ichnospecies are its general bowl-shaped
morphology with marked concavity of the flanks and bottom, marked
constriction of walls in the upper area, and the absence of bioglyphs
in the interior surface. To establish a hierarchical approach to the
taxonomy of Cubiculum, we propose an emended diagnosis for this
ichnogenus. Based on comparative analysis with structures of fossil
pupal chambers and results of actualistic experiments with carrion
insects, the ethology of C. levis is interpreted as Pupichnia.
Paleoenvironmental conditions at the paleontological site, taphonomic
data and the morphology of C. levis indicate a continental arthropod
producer with the biological and anatomical ability to bore bone. The
producer was probably a Cretaceous coleopteran with a heavily
sclerotized body and well-developed biting mouthparts. We emphasize
the importance of establishing paleoethologic and paleobiologic
inferences based on testable data provided by multiple sources, such
as biology, physiology, sedimentology, and forensic sciences. Finally,
we cite some relevant reports of traces fossils in bones interpreted
as pupal chambers and we discuss the conflicting interpretations of
their producers and ecological significance.

==

Pennsylvanian tetrapod tracks from Morocco


Abdelouahed Lagnaoui, Sebastian Voigt, Hafid Saber & Jörg W. Schneider (2014)
First Occurrence of Tetrapod Footprints from Westphalian Strata of the
Sidi Kassem Basin, Central Morocco.
Ichnos 21(4): 223-233
DOI:10.1080/10420940.2014.955096
http://www.tandfonline.com/doi/full/10.1080/10420940.2014.955096#.VF-o_PnF_To


The Sidi Kassem Basin is the only limnic basin of Westphalian age in
Morocco. It is built up of 1,250 m of alluvio-fluvial to lacustrine
deposits that have so far yielded plant fossils and invertebrate
remains only. Recent exploration for fossil tetrapod footprints in
floodplain-deposits of the basin revealed a moderately diverse
vertebrate ichnofauna composed of tracks assigned to cf. Batrachichnus
Woodworth, 1900; cf. Hylopus Dawson, 1882; Dimetropus Romer and Price,
1940; and Notalacerta Butts, 1891. The tracks can be referred to
temnospondyl, anamniote reptiliomorph, non-therapsid synapsid
(pelycosaur), and captorhinomorph trackmakers. The described
ichnoassemblage is important in at least three aspects: (1) It
suggests an Early to mid-Pennsylvanian age for the footprint-bearing
strata of the study area. (2) It is the oldest association of tetrapod
footprints from Africa. (3) It is the first evidence of the relatively
rare ichnogenera cf. Hylopus and Notalacerta outside of North America
and Europe. Judged from the variety of tetrapod tracks and previously
collected floral remains, the Sidi Kassem Basin must have represented
a well-established continental ecosystem during Pennsylvanian time.
Further exploration for trace and body fossils of Palaeozoic
vertebrates in this basin may be important for the reconstruction of
early tetrapod evolution.