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The Lower Cretaceous Huajiying Formation of the Sichakou Basin in northern Hebei Province, northern China contains key vertebrate taxa of the early Jehol Biota, e.g., , , , and This formation arguably documents the second-oldest bird-bearing horizon, producing the oldest fossil records of the two major Mesozoic avian groups Enantiornithes and Ornithuromorpha. Hence, precisely determining the depositional ages of the Huajiying Formation would advance our understanding of the evolutionary history of the Jehol Biota. Here we present secondary ion mass spectrometry (SIMS) U-Pb zircon analysis results of eight interbedded tuff/tuffaceous sandstone samples from the Huajiying Formation. Our findings, combined with previous radiometric dates, suggest that the oldest enantiornithine and ornithuromorph birds in the Jehol Biota are ∼129-131 Ma, and that the Jehol Biota most likely first appeared at ∼135 Ma. This expands the biota's temporal distribution from late Valanginian to middle Aptian with a time span of about 15 My.
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http://dx.doi.org/10.1073/pnas.1918272117 | DOI Listing |
Elife
August 2025
Department of Earth and Planetary Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, United States.
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.
View Article and Find Full Text PDFNatl Sci Rev
May 2025
Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
The Compsognathidae was originally considered an early-diverging clade of coelurosaur theropods. However, recent study suggests that Compsognathidae is not monophyletic. Here, we describe two new compsognathid-like species, sp.
View Article and Find Full Text PDFBaissid wasps (Hymenoptera: Baissidae) represent a family within the superfamily Evanioidea composed of 36 species in seven genera restricted to a period spanning from the Berriasian (earliest Cretaceous) to the Turonian (early Late Cretaceous). The status and rank of the family have been changing over time, and recent phylogenetic analyses indicate that Baissidae may be paraphyletic to Aulacidae + Gasteruptiidae. The genus Manlaya Rasnitsyn, 1980 is the most diverse and widespread in the family, including representatives from western and eastern Laurasia.
View Article and Find Full Text PDFColeoptera is a hyper-diverse group of animals with about 400,000 formally described species. Also the morphological diversity of beetles is very high, not only in the adults, but also in the larvae. To understand the evolutionary origin of this enormous diversity, investigations of fossils are crucial, but especially for the larvae such fossil are still scarce.
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