Mesozoic

A new lineage of evaniiform wasps in Cretaceous amber from Myanmar (Hymenoptera: Evanioidea)

2025-11-16T00:27:43+13:00

Evanioidea are distinctive parasitoid wasps with a comparatively rich fossil record extending to at least the Late Jurassic. Here we report a remarkable mid-Cretaceous species belonging to the clade Evaniiformes, exhibiting a mosaic of features characteristic of Evaniidae alongside traits more typical of plesiomorphic lineages outside of the evaniiforms. Antevania hirsuta gen. et sp. nov. is described and illustrated from a well-preserved female preserved in amber from Kachin, northern Myanmar. The genus is placed within the new family Antevaniidae fam. nov., and comparisons are provided with other living and fossil Evaniiformes, together with brief comments on its potential parasitoid biology.

Disruptive colouration is much more common in immature animals from the Myanmar amber forest than anticipated, indicating regular convergent evolution

2025-11-16T00:22:29+13:00

Animals have evolved a wide range of traits to avoid predation, and some of these defensive strategies can be traced in the fossil record. Recently, the first case of disruptive colouration was documented in a lacewing larva from Cretaceous Kachin amber, Myanmar. Here we report additional immature specimens from the same deposit that also exhibit disruptive colouration, expressed as alternating dark and bright stripes on the legs. The examples span a broad array of lineages, including another lacewing larva (Neuroptera: Crocinae), as well as planthoppers (Fulgoromorpha), a true bug (Heteroptera), a “predatory cricket” (Ensifera), cockroach-like forms (Dictyoptera), and several praying mantises (Mantodea). The repeated appearance of leg-based disruptive colouration in such distantly related groups suggests that this trait evolved multiple times already 100 million years ago, reflecting diverse predator-prey interactions and a complex Cretaceous food web.

**A new species of Ptycholepis (Ptycholepiformes, Actinopterygii) from the Middle Triassic (Anisian) of Luxi, Yunnan Province, China**

2026-03-16T10:10:35+13:00

The fossil taxon Ptycholepis is an extinct ray-finned fish genus ranging from the Middle Triassic to Jurassic, represented by the type species P. bollensis from the Early Jurassic of Germany, England and France and P. barboi near the Ladinian/Anisian boundary (~242 Ma) in the Monte San Giorgio area (southern Alps). Here, we report the discovery of a new species of this genus, P. huoae sp. nov. based on a well-preserved specimen from the Middle Triassic (Anisian, ~244 Ma) marine deposits in Luxi, Yunnan, China. The discovery documents the first record of Ptycholepis in China and fills the previous deficiency of marine ptycholepids in Asia. As the oldest species of Ptycholepis, the new finding predates the previously known oldest record from Europe by approximately two million years, demonstrating a longer geological range and wider biogeographical distribution than previously appreciated for the genus. A comparison of the new species with other species of Ptycholepis adds to our knowledge of the morphological diversity of the genus.

Testing the role of palaeolatitude in biotic recovery after the Permian–Triassic mass extinction: A palaeomagnetic comparison between South China and Oman

2026-03-10T15:18:47+13:00

To evaluate whether palaeolatitude influenced spatial variations in biotic recovery following the end-Permian mass extinction, we conducted a palaeomagnetic comparison between two representative regions, South China and Oman, where contrasting recovery patterns have been documented. Detailed palaeomagnetic investigations were carried out in the Lower Triassic Yelang and Maocaopu formations in the Zunyi area of the South China Block. Characteristic remanent magnetizations (ChRMs) were isolated from 31 specimens across five sites (D_s = 224.4°, I_s = -10.5°, α₉₅ = 6.7°). Rock magnetic measurements and scanning electron microscopy (SEM) observations indicate that the principal magnetic carriers are detrital magnetite and hematite. Together with the positive fold test, the ChRMs are interpreted as primary remanent magnetization acquired during deposition. This interpretation is further supported by the consistency of our results with other Early Triassic palaeomagnetic data from South China. The primary remanent magnetization directions yield a palaeolatitude of approximately 5°N for the Zunyi region in South China during the Early Triassic, placing it within the low-latitude Tethyan realm and comparable to coeval palaeolatitudes of Oman. These similar low-latitude settings suggest that latitudinal position alone is unlikely to have controlled the differences in biotic recovery between the two regions. Instead, other palaeogeographic factors, including the position relative to Pangaea and the consequent variations in ocean circulation, oxygenation state, and nutrient supply, may have played a more significant role in the spatial heterogeneity of Early Triassic ecosystem recovery.

A new geinitziid forewing reveals biostratigraphic correlation between Daohugou and Shar Teg

2026-03-23T13:54:12+13:00

The Middle–Late Jurassic insect assemblages of the Asian interior, such as the Daohugou and Shar Teg biotas, provide critical windows into insect evolution. These biotas share similar faunal compositions, yet their similarities are largely limited to the generic level. This lack of species-level evidence has hindered precise stratigraphic correlation. In this study, we describe a complete forewing of a geinitziid fossil from the Haifanggou Formation at the Daohugou locality, Ningcheng, Inner Mongolia. The specimen is identified as Sinosepididontus shartegicus Aristov et al., 2009, a species previously known only from a basal wing fragment recovered from the lower Shar Teg sequence in southwestern Mongolia. Based on this well-preserved new material, we provide an emended diagnosis and supplementary description for S. shartegicus, offering the first full characterization of its wing venation. The discovery of S. shartegicus in the Daohugou biota substantially reinforces the biotic link between the Daohugou and Shar Teg assemblages. Based on regional geological data, we correlate the Shar Teg sequence with the Haifanggou Formation, and we further correlate the overlying Ulan Malgait sequence with the Tiaojishan Formation.

Mesozoic Remagnetization in the South China Block

2026-03-10T15:19:40+13:00

The South China Block has experienced multiple tectonic events. During the Mesozoic, the Indosinian and Yanshanian orogenic events played a significant role in shaping its present-day tectonic framework, producing widespread deformation, metamorphism, and magmatism. These tectonic processes also drove widespread fluid migration through sedimentary successions. Such tectonically induced fluid–rock interactions profoundly modified primary mineral assemblages and promoted the formation and transformation of magnetic minerals, leading to widespread Mesozoic remagnetization in sedimentary strata across the South China Block. These remagnetization records provide a valuable archive for constraining the timing, duration, and spatial extent of tectonic processes and their associated diagenetic responses in sedimentary rocks. This paper presents a systematic review of Mesozoic remagnetization phenomena in sedimentary rocks of the South China Block in relation to the Indosinian and Yanshanian tectonic events. We further synthesize current understanding of the role of tectonic processes in influencing burial diagenesis, hydrocarbon generation, migration, and accumulation, and the destruction of hydrocarbon reservoirs, as well as mineralization. Finally, we highlight the value of remagnetization as a quantitative spatiotemporal tool for reconstructing geological processes involving fluid flow and thermal evolution.

Fossil Mecoptera of China: A review and taxonomic checklist

2026-03-25T16:44:20+13:00

The study of fossil Mecoptera in China started relatively late, with the first mecopteran fossil species not reported until 1980. With the increasing number of palaeoentomological researchers in China and the discovery of several important fossil localities, studies on fossil Mecoptera have made considerable progress. This paper provides a comprehensive review of the research history on fossil Mecoptera in China and presents a taxonomic checklist of all known Chinese species. It also provides a taxonomic checklist of Chinese fossil Mecoptera, including 170 species belonging to 65 genera and 17 families from the Permian to the Cretaceous. Overall, although considerable progress has been achieved in the study of fossil Mecoptera in China over the past half century, further fossil discoveries and studies are still required to clarify their diversity, stratigraphic distribution, and evolutionary history.

Eosassula szwedoi gen. et sp. nov. from the Danish earliest eocene Fur Formation

2026-03-23T13:27:26+13:00

Recently, we described a new genus and species of fossil planthoppers (family Nogodinidae) (Simonsen et al., 2025). Unfortunately, we did not mention the type repository, and therefore the names proposed are unavailable. To correct this and make the names available, we here provide a redescription of the genus and species by bibliographic reference and provide the missing information.

Looks can be deceiving: convergent hair tufts mask a new lineage of Cretaceous mites

2026-03-26T17:45:11+13:00

The similar morphological traits produced by convergent evolution represent a primary source of taxonomic confusion. The porcupine-like mites from mid-Cretaceous Burmese amber, which can be readily recognized by four tufts of extremely long setae on their backs, have recently been reported by several researchers as members of the family Chyzeriidae Womersley, 1954. However, detailed morphological examination of newly discovered specimens reveals that these similarities are superficial. Some important higher-level taxonomic characters (e.g., retractable gnathosoma, needle-like chelicerae, and two pairs of genital acetabula) of these extinct mites are not clearly presented in reported specimens, obscuring their true phylogenetic position. Here we demonstrate that the hair tufts in these Cretaceous mites represent a case of convergent evolution and that the fossils belong to a previously unrecognized lineage. We revisit 62 new fossils of this group using various imaging technologies, including stereomicroscopy, fluorescence microscopy, and laser confocal scanning microscopy, and we also examined three slide-mounted specimens from three extant families: Chyzeriidae Womersley, 1954, Smarididae Kramer, 1878, and Calyptostomatidae Oudemans, 1923, were also examined for morphological comparison. Newly discovered morphological evidence supports the establishment of a new family Acarohystricidae fam. nov. to accommodate these extinct Cretaceous mites, which is placed in its own superfamily—Acarohystricoidea superfam. nov.—distantly related to the extant Chyzeriidae. A new genus and species, Acarohystrix magnifica gen. et sp. nov., is erected and the genera Punkochyzeria Kolesnikov, Turbanov & Vorontsov, 2025 and Cretachyzeria Liu, Fan & Ren, 2025 are transferred to this new family. Additionally, a new species, Punkochyzeria obtusa sp. nov., is described and P. khoyi Kolesnikov, Turbanov & Vorontsov, 2025 is proposed as a junior synonym of P. makolae Kolesnikov, Turbanov & Vorontsov, 2025. A revised diagnosis of Punkochyzeria is provided. Furthermore, phylogenetic analyses based on a limited set of morphological characters provide preliminary evidence for a sister-group relationship between Acarohystricidae fam. nov. and the extant family Calyptostomatidae Oudemans, 1923 within Erythraeina, justifying the establishment of Acarohystricoidea superfam. nov. We also include the ontogenetic and sexually dimorphic character states within the new family.