HE Fa-lin,HUANG Xin-jie & LI Xiao-yong (2017)
Occurrence rule and buried characteristics of dinosaur fossils in the Ganzhou Basin, Jiangxi Province.
East China Geology 38(4): 250-254. (in Chinese)
The Late Cretaceous Maodian and Hekou Formations of the Ganzhou Basin in southern Jiangxi Province were found to host a large number of dinosaur fossils, which are collectedly distributed and well preserved. In particular, well preserved fossilized dinosaur eggs are laid elaborately in circular nests. The paper mainly discusses the fossil-bearing strata and lithology, preserving form and buried characteristics of dinosaur fossils in the basin. It is believed that dinosaur fauna or dinosaur fossils occur mainly within the Late Cretaceous Maodian Formation and Hekou Formation in the basin. The dinosaur fossils preserved in the Maodian and Hekou formations are characterized by occurrence assemblages: single type to various types of dinosaur fossils, and eggs to egg-bone mixing, even embryo-bearing eggs and dinosaur skeletons buried with tortoise fossils. This complex occurrence will provide real materials for further investigating the evolution of the basin and living environment of dinosaurs.
Rui Zhang , Qiaoli Ji, Dianlei Han, Haijin Wan, Xiujuan Li, Gang Luo, Shuliang Xue, Songsong Ma, Mingming Yang & Jianqiao Li (2018)
Phalangeal joints kinematics in ostrich (Struthio camelus) locomotion on sand.
PLoS ONE 13(2): e0191986
In ostriches, the toes are the only body parts that contact loose sand surfaces. Thus, toe interphalangeal joint motions may play vital biomechanical roles. However, there is little research on ostrich phalangeal joint movements while walking or running on sand. The results from the three-dimensional motion track analysis system Simi Motion show that gait pattern has no significant effect on the key indicators (angles at touch-down, mid-stance, lift-off and range of motion) of the toe joint angles. The motion of the toe phalanges when walking and running on sand is basically the same. The ground medium is the key factor that changes the toe postures adopted by ostriches during the stance phase in slow to fast locomotion. The 3rd toe and the 4th toe are connected by the interphalangeal ligament, and the motions of the MTP3 and MTP4 joints are highly synchronized on a loose sand substrate. The 3rd toe and 4th toe are coupled to maintain static balance in slow locomotion and dynamic balance in fast locomotion. In addition, the gait pattern has a marked effect on the range of forward displacement of the toenail (YTN). The ostrich toenail plays an important role in preventing slip and provides traction at push-off in a sandy environment. The metatarsophalangeal joint plays an important role in energy saving during fast locomotion on loose sand substrates. Simulation reveals that the particle velocity field, particle force field and sand particle disturbance in the running gait are denser than those in the walking gait.
Christian Neumann and Oliver Hampe (2018)
Eggs for breakfast? Analysis of a probable mosasaur biting trace on the Cretaceous echinoid Echinocorys ovata Leske, 1778.
Fossil Record 21: 55-66
Fossil biting traces (praedichnia) represent indirect evidence of predation and shed light on fossil predatorâprey interactions and fossil food webs. Especially from echinoderm skeletons, biting traces are well known. Here, we describe the oral surface of a large Cretaceous (Maastrichtian) holasteroid echinoid Echinocorys ovata Leske, 1778 from Hemmoor (northern Germany) which exhibits four circular punctures arranged in a semi-circular arc. Whereas three of the punctures penetrated the skeleton, one puncture only just hit the margin of the echinoid test at the ambitus, leaving a long incision furrow in the skeleton. The punctures were not lethal to the sea urchin as is indicated by progressed skeletal regeneration and closure of the fractures. The overall appearance of the punctures suggests that they were produced during a single mechanical event, most likely by the biting action of the teeth of a large vertebrate animal. We analysed the shape and arrangement of the biting trace and conclude that it was probably produced by a marine reptile possessing a prognath tooth position, most likely by a globidensine mosasauroid. Our finding not only sheds light on mosasaur feeding behaviour and prey selection but also increases the knowledge of the food webs in the chalk sea ecosystem during the uppermost Cretaceous.