Conference Agenda

Normandy, in north-western France, has yielded a fairly large number of dinosaur remains since the 18th century. Most of them come from Jurassic rocks. However, several important dinosaur specimens have been collected from Cretaceous formations cropping out in the cliffs along the coast of the English Channel. The first record is an isolated caudal vertebra from the Albian of Bléville (Le Havre, Seine-Maritime), which was in the collection of the local palaeontologist Bucaille as early as 1877. It was identified as belonging to a sauropod in 1988 and later referred to Normanniasaurus genceyi Le Loeuff, Suteethorn & Buffetaut, 2013, a titanosaurian sauropod taxon based on vertebrae and pelvic elements from the same area and geological horizon. Caletodraco cottardi Buffetaut, Tong, Girard, Hoyez & Párraga, 2024 is a furileusaurian abelisaurid theropod described on the basis of a tooth, sacral and caudal vertebrae and ilia from the lower Cenomanian Chalk at Saint-Jouin-Bruneval (Seine-Maritime). To this scanty record can probably be added a bone found in the Cenomanian Chalk of Villers-sur-mer (Calvados) and referred to a bird on the basis of histological characters by Hupier in 1933 ; no detailed description was published and the whereabouts of the specimen are unknown. All these specimens come from marine deposits and the dinosaurs in question probably lived on emergent areas of the Armorican Massif, some 100 km to the west. Although scanty, this Cretaceous record from Normandy provides useful information about the dinosaur faunas which inhabited north-western Europe during the middle part of the Cretaceous.

A combination of sectioning and microscopy techniques, along with the application of finite-difference-time-domain modeling on a fossil feather, results in the novel estimation of the range of iridescent colors from the fossilized melanosome type and organization preserved in the elongate head crest feathers of a new Cretaceous enantiornithine bird. The densely packed rod-like melanosomes are estimated to have yielded from red to deep blue iridescent coloration of the head feathers. The shape and density of these melanosomes also may have further increased the feather’s structural strength. This occurrence on a likely male individual is highly suggestive of both a signaling function of the iridescent crest, and a potential behavioral role in adjusting the angle of light incidence to control the display of this iridescent structural coloration.

This study results from the first complete survey of vertebrate fossils (N > 4200) from the Lower Cretaceous terrestrial deposits of southeastern Australia. These materials, some of the richest samples of polar vertebrate fossils known anywhere in the Mesozoic, derive from two layers separated by ~10 my: the upper Barremian-lower Aptian upper Strzelecki Group and the lower Albian Eumeralla Formation. Both were deposited in rift-basin fluvial systems during the separation of Australia from Antarctica.

Most fossils are well-preserved, suggesting they were neither exposed to extensive surface weathering nor transported far from their initial burial sites, and thus likely retain information about their original source ecosystems. However, secondary deposition in high-energy river systems likely affected both small and large-bodied forms. The presence of rare elements from large theropod and ornithopod dinosaurs suggests that the absence of sauropods in both strata is genuine; conversely, the lack of small lepidosaurs and lissamphibians may be due to winnowing and needs to be further investigated.

Faunal profiles show high abundances of bony fishes and turtles—i.e. aquatic and semi-aquatic taxa—followed by dinosaurs (ornithopods being the most common), many of which show potentially close relationships with non-polar forms. Relictual giant temnospondyls in the upper Strzelecki gave way to much smaller crocodilians in the Eumeralla. Yet despite some important distinctions, these vertebrate communities seem to be polar ‘variants’ of non-polar ecosystems elsewhere in Gondwana.

Dinosaur nests and their associated site fidelity are usually discovered in low-energy alluvial plains. However, the Gojeong-ri dinosaur egg site in Korea reveals an unusual nesting strategy and evidence of site fidelity, preserving numerous sauropod egg assemblages within high-energy braided river conglomerates. This includes an in-situ clutch of faveoloolithid eggs from a mid-channel bar deposit, with 127 out of 175 eggs in the study area preserved in high-energy conglomerates—suggesting periodic destruction of nesting colonies. All egg assemblages were categorized into three taphofacies based on the textural differences between the egg interiors and surrounding materials, a key taphonomic criterion: 1) in-situ clutches (Taphofacies I), 2) parautochthonous clutches (Taphofacies II), and 3) allochthonous clusters (Taphofacies III). Synthesizing insights from modern bird and turtle nesting behaviors with taphonomic analyses and interpretations, we propose that sauropods at Gojeong-ri utilized surrounding streams as natural moats to minimize predation risks and protect their nests. The sauropod’s ability to balance the risks and benefits for reproductive success indicates their highly sophisticated egg-laying behavior.

Mesozoic teleost fossils are globally widespread. However, larval fish fossils with preserved soft tissues remain rare in the geological history, thereby constraining our understanding of the early evolution and life history traits of teleost. Here, we describe a group of incompletely ossified teleost larvae fossils from the Lower Cretaceous in northwest China, exhibiting clear soft tissue preservation in the eyes, trunk and dorsum of the abdominal cavity, with ultrastructural features consistent with melanosomes. The consistent presence of similar pigment patterns across distinct developmental stages provides a foundation for the identification of incompletely preserved larval fish fossils. Notably, the pigment pattern observed in the dorsum of the abdominal cavity is commonly found in extant teleost larvae fishes. Ancestral state reconstruction based on peritoneum pigmentation distribution patterns in 470 existing fish species reveals teleost fishes usually present a row of melanophores in the upper abdominal cavity in the early stage of their evolutionary history. This pigmentation pattern may represent a primitive trait of teleosts, providing photo-protective function against ultraviolet radiation for hematopoietic tissues during larval development. It is worth noting that most species that differentiated in the late Mesozoic were generally covered with melanophores in the abdominal cavity. This shift in pigmentation may correlate with Mesozoic environmental stressors.

Keywords: teleost, Early Cretaceous, larval fish fossil, peritoneum

This work is supported by the National Natural Science Foundation of China (42372006 and 42272029), the Fundamental Research Funds for the Central Universities (lzujbky-2022-ey18) and the Gansu Province Postgraduate Innovation Star Program (2025CXZX-090).

The Balve site is an Early Cretaceous Karstic (Barremian to Aptian) fissure fill within Devonian limestone situated in Northwestern Germany. The deposits most likely represent a cave infill in an upland environment, which was situated at least 100 m above sea level. Hence, this locality offers valuable insights into a Cretaceous hinterland ecosystem. Annual excavations at the site are being carried out by the LWL Museum of Natural History Münster since the year 2000 and have yielded remains of a diverse vertebrate fauna. This faunal assemblage includes osteichthyes, chondrichthyes, amphibians, multiple mammal taxa, crocodilians, pterosaurs and dinosaurs. Among the latter are numerous teeth and isolated bones referrable to Theropoda. Based on an analysis of the former, a previous report has already indicated the presence of Tyrannosauroidea among the fossil material. The results of our morphometric analysis of an isolated, partial quadrate suggests strong affinities with the British Eotyrannus, supporting the presence of tyrannosauroids. An as of yet indeterminate taxon of large theropod dinosaur is represented by an additional, larger and almost complete quadrate bone. Another, recent addition to the theropod fauna present at the Balve locality is ornithomimosaurs, represented so far by a manual ungual and a distal third metatarsal fragment. Ongoing analyses of the material potentially indicate the presence of further groups at the site, contributing to our growing understanding of this Early Cretaceous upland ecosystem.