A. de Celis, I. NarvÃez & F. Ortega (2017)
Pelvic and femoral anatomy of the Allodaposuchidae (Crocodyliformes, Eusuchia) from the Late Cretaceous of Lo Hueco (Cuenca, Spain).
Journal of Iberian Geology (advance online publication)
The fossil record of postcranial remains assigned to Allodaposuchidae is currently sparse. However, the Late Cretaceous paleontological site of Lo Hueco (Cuenca, Spain), from where two new taxa of allodaposuchid have been described, has yielded numerous postcranial remains assignable to this clade. Among them, the large amount of pelvic and femoral material is notable, providing the opportunity to study these allodaposuchid elements and assess their morphological similarity with other eusuchian remains.
The comparison with extant crocodylians was accomplished using traditional morphometric techniques, whereas the comparison with other fossils and establishment of morphotypes was done using morphological criteria.
The results of the cluster and principal components analyses show morphological differences between extant crocodylians and allodaposuchids from Lo Hueco, allowing the segregation of these lineages. The similarities found between the pelvic and femoral remains from Lo Hueco, and those referred to Allodaposuchus precedens and other putative allodaposuchids from the Iberian Peninsula, allows referral of these remains to allodaposuchids. The differences found among the femoral and pelvic remains of Lo Hueco enables us to recognize two morphotypes per each element.
This study allows a better understanding of allodaposuchid postcranial elements that were previously poorly known. The ilia, ischia and femora from Lo Hueco allodaposuchids are distinct from those of other crocodylian lineages. Finally, the fact that there are two morphotypes per each element at Lo Hueco is congruent with the presence of two different allodaposuchids at the site.
From a some weeks back...
Li-Da Xing, Yuan-Chao Hu, Jian-Dong Huang, Qing He, Martin G. Lockley, Michael E. Burns & Jun Fang (2017)
A redescription of the ichnospecies Koreanaornis anhuiensis (Aves) from the Lower Cretaceous Qiuzhuang Formation at Mingguang city, Anhui Province, China.
Journal of Palaeogeography (advance online publication)
The Cretaceous bird trackway originally labeled Aquatilavipes anhuiensis, in 1994, had previously been examined, photographed and replicated, but never described or illustrated in detail. However, it has been part of a widening discussion about the distribution of Aquatilavipes and Koreanaornis in China (and Korea). Here we illustrate and formally describe the holotype in detail and assign it to Koreanaornis (Koreanaornis anhuiensis) as informally proposed by previous authors. We also demonstrate that most authenticated reports of Koreanaornis, including the Anhui occurrence, are from the Lower Cretaceous, not from the Upper Cretaceous as previously reported.
Jana Goyens & Peter Aerts (2017)
Head stabilisation in fast running lizards.
Zoology (advance online publication)
Head stabilisation facilitates vestibular perception during running.
A sprawled body posture causes large body undulations during running.
Despite large body undulations, running lizards strongly stabilise head rotations.
Lateral head translations are not stabilised in running lizards.
When perturbed, rotations and translations of both head and body are stabilised.
The cyclic patterns of terrestrial animal locomotion are frequently perturbed in natural environments. The terrain can be complex or inclined, the substrate can move unexpectedly and animals can misjudge situations. Loosing stability due to perturbations increases the probability of capture by predators and decreases the chance of successful prey capture and winning intraspecific battles. When controlled corrective actions are necessary to negotiate perturbations, animals rely on their exteroceptive and proprioceptive senses to monitor the environment and their own body movements. The vestibular system in the inner ear perceives linear and angular accelerations. This information enables gaze stabilisation and the creation of a stable, world-bound reference frame for the integration of the information of other senses. During locomotion, both functions are known to be facilitated by head stabilisation in several animals with an erect posture. Animals with a sprawled body posture, however, undergo very large body undulations while running. Using high speed video recordings, we tested whether they nevertheless stabilise their head during running, and how this is influenced by perturbations. We found that running Acanthodactylus boskianus lizards strongly stabilise their head yaw rotations when running on a flat, straight runway: the head rotation amplitude is only 4.76 Â 0.99Â, while the adjacent trunk part rotates over 27.0 Â 3.8Â. Lateral head translations are not stabilised (average amplitude of 7.4 Â 2.0 mm). When the lizards are experimentally perturbed by a large and unexpected lateral substrate movement, lateral translations of both the head and the body decrease (on average by 1.52 Â 0.81 mm). At the same time, the rotations of the head and trunk also decrease (on average by 1.62Â Â 7.21Â). These results show that head stabilisation intensifies because of the perturbation, which emphasises the importance of vestibular perception and balance in these fast and manoeuvrable animals.