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[dinosaur] Dinosaur tracks from Lower Cretaceous Xiguayuan Formation + Cretaceous crocodylomorph parasites

Ben Creisler

Some recent papers:

Lida Xing, Martin G. Lockley, Zuohuan Qin, Hendrik Klein, Anthony Romilio, W. Scott Persons IV, Xin Nie & Xiaoqiao Wan (2019)
Dinosaur tracks from the Lower Cretaceous Xiguayuan Formation in the Luanping Basin, Hebei Province, China.
Cretaceous Research (advance online publication)
doi: https://doi.org/10.1016/j.cretres.2019.06.009

The Qiaomaigoumen dinosaur tracksite was previously described briefly in 1995 and 2006 based on examination of a single surface (â200 m2) with five trackways representing two quadrupedal ornithopods (Caririchnium isp.) and three bipedal theropods. While confirming this general description, this study also revealed that two additional sites (Sangyuan I and II) had been found, and that tracks from all three sites had been collected for local institutions. This created the opportunity to describe the ichnofauna more completely, including a variety of theropod morphotypes (cf. Jialingpus isp. and cf. Eubrontes isp.) not previously identified in this area. It is also inferred that the tracksites occur in the Xiguayuan Formation, not in the Jiufotang Formation as previously suggested. This indicates an equivalency with the Jehol Biota and some track elements corresponding generally to Jehol body fossils.


Daniel F. F. Cardia, Reinaldo J. Bertini, Lucilene G. Camossi & Luiz A. Letizio (2019)
Two new species of ascaridoid nematodes in Brazilian Crocodylomorpha from the Upper Cretaceous.
Parasitology International (advance online publication)
doi: https://doi.org/10.1016/j.parint.2019.101947


Two new ascaridoids are described based on fossils of eggs in 80â70 mya Crocodylomorpha coprolites.
This paper reports the oldest Ascaridoidea species parasitic in Crocodyliformes.
Bauruascaris is the second oldest genus Ascaridoidea recorded in the literature.


Two new ascaridoid species, Bauruascaris cretacicus n. gen. et n. sp., and Bauruascaris adamantinensis n. gen. et n. sp., are described based on the fossils of eggs preserved in 80â70 million year old phosphatized coprolites of Crocodyliformes, chronologically assigned to the Upper Cretaceous (Campanian/Maastrichtian age), collected from sedimentary rocks of the Bauru Group, Adamantina Formation in the municipality of Santo AnastÃcio, in the southwestern region of the state of SÃo Paulo, Brazil, South America. This paper describes the oldest ascaridoid species ever recorded in Crocodylomorpha. Hence, this article contributes to the body of knowledge about the evolutionary history of this nematode group. It also offers a clue about the composition of the parasite fauna of these reptiles from the Late Cretaceous, which is still unknown despite numerous studies about various aspects of their biology and the pioneering paleoparasitological analysis of animal coprolites by South American researchers.


Also, forthcoming articles in the journal Advances in Polar Science.
Only as abstracts for now--the pdfs are not yet posted:

Cretaceous Antarctic plesiosaurs: stratigraphy, systematics and paleobiogeography.
Advances in Polar Science 30(3): **-**
doi: 10.13679/j.advps.2018.0049

The last twenty million years (Maastrichtian-Santonian) of Southern Hemisphere plesiosaur history is especially well recorded in the Weddellian Province (Patagonia; Western Antarctica and New Zealand). The oldest Late Cretaceous plesiosaurs, two specimens referred to Polycotylidae indet., come from the Santonian levels of the Santa Marta Formation, while the oldest elasmosaurids come from the lower Campanian of the same formation. In the lower Maastrichtian of the Snow Hill Island Formation the non-aristonectine elasmosaurid Vegasaurus molyi is recorded together with other non-diagnosable elasmosaurid specimens, but no aristonectines are present. Aristonectines appears in the Antarctic record in the upper Maastrichtian of the LÃpez de Bertodano Formation and are represented by Morturneria and cf. Aristonectes. The specimens from the upper Campanian previously referred to Aristonectinae indet. are referred to Elasmosauridae indet., shortening the temporal record of Aristonectinae in Antarctica. Therefore aristonectines appears in the Antarctic record in the upper Maastrichtian of the LÃpez de Bertodano Formation and are represented by Morturneria and cf. Aristonectes. The Antarctic Cretaceous elasmosaurids show a paleobiogeographic connection with South America and New Zealand (Weddellian Province). This connection is indicated by the shared presence of the Aristonectinae Kaiwhekea katiki (New Zealand) and Aristonectes (Argentina and Chile). Recent phylogenetic analysis recovered the aristonectines within the Weddellonectia clade, which includes the aristonectines and the non-aristonectines Vegasaurus molyi (Isla Vega, Antarctica); Kawanectes lafquenianum (Argentina); Morenosaurus stocki and Aphrosaurus furlongi (California). Among the Weddellonectia, the aristonectines show a relatively large body size and an extremely derived features and probably occupied a trophic niche that differed from the trophic niche of other elasmosaurids. By way of contrast Kawanestes lafquenianum is an extremely small body sized elasmosaurid restricted to marginal marine (probably estuarine) environments. Therefore the Weddellonectia show high morphological and probably high ecological diversity.


Matthew C. LAMANNA, Judd A. CASE, Eric M. ROBERTS, Victoria M. ARBOUR, Ricardo C. ELY, Steven W. SALISBURY, Julia A. CLARKE, D. Edward MALINZAK, Abagael R. WEST & Patrick M. OâCONNOR (2019)
Late Cretaceous non-avian dinosaurs from the James Ross Basin, Antarctica: description of new material, updated synthesis, biostratigraphy, and paleobiogeography.
Advances in Polar Science 30(3): **-**
doi: 10.13679/j.advps.2019.0007

Although the fossil record of non-avian dinosaurs from the Cretaceous of Antarctica is the poorest of any continent, fossils representing at least five major taxonomic groups (Ankylosauria, early-diverging Ornithopoda, Hadrosauridae, Titanosauria, and Theropoda) have been recovered. All come from Upper Cretaceous (ConiacianâMaastrichtian) marine and nearshore deposits belonging to the Gustav and Marambio groups of the James Ross Basin at the northern tip of the Antarctic Peninsula. The majority of these finds have come from the Campanian-Maastrichtian Snow Hill Island and LÃpez de Bertodano formations of James Ross and Vega islands.

Given the rarity of Antarctic Cretaceous non-avian dinosaurs, discoveries of any fossils of these archosaurs, no matter how meager, are of significance. Here we describe fragmentary new ornithischian (ankylosaur and ornithopod) material from the upper Campanian-lower Maastrichtian Cape Lamb Member of the Snow Hill Island Formation and the Maastrichtian Sandwich Bluff Member of the LÃpez de Bertodano Formation. One of these specimens is considered to probably pertain to the holotypic individual of the early-diverging ornithopod Morrosaurus antarcticus. We also provide an up-to-date synthesis of the Late Cretaceous non-avian dinosaur record of the James Ross Basin and analyze the biostratigraphic occurrences of the various finds, demonstrating that most (including all named taxa and all reasonably complete skeletons discovered to date) occur within a relatively condensed temporal interval of the late Campanian to early Maastrichtian. Most or all James Ross Basin dinosaurs share close affinities with penecontemporaneous taxa from Patagonia, indicating that at least some continental vertebrates could disperse between southern South America and Antarctica during the final stages of the Mesozoic.


The fossil record of birds from the James Ross Basin, West Antarctica.
Advances in Polar Science (abstract for accepted paper)

The fossil record of birds from Antarctica is concentrated in the James Ross Basin, located north-east of the Antarctic Peninsula. Birds are here represented by an extensive Paleogene record of penguins (Sphenisciformes) and Cretaceous-Paleogene record of Anseriformes, followed by other groups with a minor representation (Procellariiformes, Falconiformes, and Pelagornithidae), and others previously assigned controversially to "Ratites", Threskiornithidae, Charadriiformes, Gruiformes, Phoenicopteriformes, and Gaviiformes. We provide a complete update of these record, commenting on the importance of some of these remains for the evolution of the major clades.ÂÂ

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