Diaphanopterodea were members of the broader group Megasecopteromorpha, an assemblage of extinct insects that flourished during the Late Palaeozoic, roughly 300 million years ago. Compared with other lineages of this group, diaphanopterodeans are known from relatively few species and fossil specimens, which makes every new find valuable. What has long fascinated researchers about these insects is their ability to fold their wings backwards along the abdomen at rest, a capacity known as neoptery. This trait was once considered the ancestral condition for all winged insects, but most specialists now accept that it evolved convergently, appearing independently within Megasecopteromorpha and within the larger neopteran radiation. Over the roughly 75 million years of their evolutionary history, diaphanopterodeans also diversified into remarkably small forms with greatly reduced wing venation, a body plan that superficially recalls that of modern wasps and bees.

The new specimen, catalogued as YQZYW 15, was collected from a siltstone layer in the middle part of the Shanxi Formation at a locality called Shuiquan Gully, in the Duanjiabei District near the city of Yangquan. The Shanxi Formation is a sequence of deposits laid down under conditions of continental and oceanic interaction, consisting mainly of coal, mudstone, siltstone and sandstone. It conformably overlies the Taiyuan Formation and underlies the Xiashihezi Formation. The fossil-bearing layer is grey and packed with plant fossils, including the seed fern foliage Neuropteris ovata, several species of the tree fern Pecopteris, and the cordaitalean conifer relative Cordaites. Based on its lithological characters, this layer is assigned to the Asselian age of the Permian, the earliest stage of the Cisuralian epoch, dating the insect to approximately 299 to 293 million years ago. The upper part of the fossiliferous interval contains marine invertebrates such as brachiopods and gastropods, painting a picture of a humid, vegetated coastal environment where insects thrived among dense forests.

Only a single right forewing was preserved, split between a part and counterpart slab, with the distal portion missing. Even so, its preservation quality proved sufficient for detailed analysis. The preserved wing measures 15.4 millimeters in length and 5.5 millimeters in width, and its venation pattern carries a suite of diagnostic features: a dark area between the anterior wing margin and the radius, a subcostal vein that vanishes before reaching the radius, a forked cubitus posterior, and an exceptionally well-developed anal area bearing eight terminal branches. The researchers documented the fossil using high-resolution photography under both dry and ethanol immersion conditions, combining images from both sides of the slab to capture the maximum anatomical detail, and complemented the photographs with careful hand-drafted interpretive drawings made with a stereomicroscope equipped with a drawing tube.

Assigning the specimen to its correct position in the insect family tree required a broad comparative analysis of wing venation across all known members of the families Parelmoidae and Elmoidae, the two closest relatives of the new material. The key turned out to be a very short, oblique cross-vein in the region between the anterior and posterior cubital veins, a feature that places the specimen firmly within Diaphanopterodea while excluding affinity with the Sinodiaphidae. A long fusion of the anterior cubital vein with the combined radial and medial stem rules out the Diaphanopteridae, and the overall configuration of veins points squarely to the Parelmoidae. Affinity with the Elmoidae was also tested and rejected: elmoid insects have a narrow anal area with a simple anal vein, whereas the new specimen shows a broad anal fan with numerous long veins, a signature of the Parelmoidae.

Within the Parelmoidae, comparisons with individual genera further confirmed that the Chinese wing belongs to something new. In the genera Parelmoa, Pseudelmoa and Elmodiapha, known from the famous Early Permian localities of Elmo and Midco in Kansas and Oklahoma, and from Obora in the Czech Republic, the split between the anterior and posterior branches of the media lies well beyond the split of the radius, whereas the two splits occur at the same level in the Chinese fossil. The new species also differs from these genera and from Permuralia of Russia by its brief cross-vein connection between the radius posterior and media anterior, and by its forked cubitus posterior. Comparison with Permelmoa magnifica from the Lodève locality in France prompted the researchers to re-examine the French holotype using reflectance transformation imaging, a technique that captures how a fossil surface reflects light from dozens of directions and allows virtual relighting of the specimen.

That re-examination yielded a series of corrections to the earlier interpretation of Permelmoa magnifica. The original description reported three branches of the radius posterior, but the new analysis found four; the course of the anterior cubital vein was reinterpreted; and a structure previously identified as a basal portion of the posterior media was reassigned as a twin, shifted impression of the anterior cubitus, a preservation artifact documented in other material from Lodève. The authors also proposed an alternative homology for the medial vein system, suggesting that the media anterior may run fused with the radius for some distance rather than arising from a free medial stem. However the debate on the French species resolves, the Chinese fossil remains distinct from it in numerous respects, justifying the erection of a new genus and species.

Beyond the taxonomy, the good preservation of Sinoelmoa yangquanensis allowed the team to resolve a lingering uncertainty about the arrangement of the main veins near the wing base in Diaphanopterodea. In most members of the order, the space between the cubital stem and the combined radial-medial stem is extremely narrow, and the free distal portion of the anterior cubitus diverges right next to the point where the radius and media separate, making it nearly impossible to tell whether the entire cubital stem, or only its anterior branch, fused with the radial-medial stem. In the new specimen, an independent cubital stem is clearly visible, with a simple anterior cubitus running alongside the radial-medial stem for some distance before diverging abruptly. This observation overturns the assumption of an early common stem combining all three vein systems, and instead corroborates previous observations of a more or less brief connection between the anterior cubitus and the radial-medial stem, a pattern likely general to most diaphanopterodean families and probably present in the specialized families Martynoviidae and Asthenohymenidae as well.

The biogeographic implications of the find may prove just as important as its anatomical ones. Until now, the Parelmoidae were known only from localities in what are now the Czech Republic, the United States, France and Russia, all in the western and central parts of the Palaeozoic world. Sinoelmoa yangquanensis, being Asselian in age, constitutes the earliest occurrence of the family, and being situated along the eastern margin of the Palaeotethys on the North China Block, it is also the most oriental. Together, these two superlatives suggest that these rather infrequent insects enjoyed a far broader geographic distribution than the sparse fossil record had indicated, at least along the lower latitudes of the Northern Hemisphere, when the supercontinent Pangaea was still assembling and dense coal-forming forests stretched across the tropical belt.

The discovery also underscores how much remains to be learned from even a single wing. Because diaphanopterodeans are rare and their fossils often deformed or incomplete, paleontologists must rely on subtle details of venation, the branching patterns and cross-veins etched into chitin hundreds of millions of years ago, to reconstruct their evolutionary relationships. Sinoelmoa yangquanensis demonstrates that careful comparison of these features, supported by modern imaging techniques and re-examination of old museum specimens, can still overturn long-held assumptions about how these ancient insects were built. It is a reminder that the earliest experiments in wing folding, a capability that today defines the vast majority of insect species, were unfolding in parallel lineages across a Permian world whose full diversity is only beginning to come into view, one slab of siltstone at a time.

Subject of Research: Early Permian diaphanopterodean insects and the discovery of a new Parelmoidae species from China

Article Title: The first Permian Diaphanopterodea ( Insecta , Megasecopteromorpha ) from China

Article References: Yang, N., Cui, Y., Xu, Z., Xu, Y., Ren, D., & Béthoux, O. (2024). The first Permian Diaphanopterodea (Insecta, Megasecopteromorpha) from China. Fossil Record, 27(2), 247-258. https://doi.org/10.3897/fr.27.128892

Image Credits: AI Generated

DOI: 10.3897/fr.27.128892

Keywords: Diaphanopterodea, Parelmoidae, Sinoelmoa yangquanensis, Permian insects, Shanxi Formation, fossil insects, wing venation, palaeontology, China, North China Block, Cisuralian, Megasecopteromorpha

The specimen was recovered from a gray siltstone layer overlying Coal No. 4 at the Antaibao Surface Mine near Shuozhou City, a site within the famed Shanxi Formation. That formation represents a marine-nonmarine transitional environment where swampy peat accumulated on floodplains fed by braided rivers. The regional plant assemblage, characteristic of the Cathaysian Flora, includes index species such as Emplectopteris triangularis and Taeniopteris mucronata, and high-precision uranium-lead dating of nearby strata has pinned the Shanxi Formation to the Asselian stage of the Early Permian. The fossil itself consists of two facing parts of a cast, each preserving three partially preserved fruits arranged in parallel and oriented the same way.

Morphologically, each fruit is strap-shaped, with nearly parallel sides, preserved lengths of 4.2 to 4.8 millimeters and widths of 1.2 to 1.3 millimeters. All three structures display a terminal zone free of any reproductive bodies, a detail the team interprets as a seed-free, styleless fruit tip. Inside the fertile regions are three to six globular bodies of varying size and form. Larger bodies measure 1.15 to 1.4 millimeters across, while smaller ones range from 0.36 to 0.57 millimeters. The larger bodies bear vermiform, worm-like surface sculpture interpreted as a seed coat, and their discoid, biconcave form is striking, since such doubly concave seeds are known in some living angiosperms, such as the moonseed family Menispermaceae, but have never been documented in any extinct or extant gymnosperm.

To examine the internal anatomy without damaging the precious specimen, the researchers subjected it to micro-computed tomography at the State Key Laboratory of Continental Dynamics at Northwest University in Xi’an. Scanning at 170 kilovolts and 200 microamperes, they collected 2,000 projections at a resolution of 26.22 micrometers and reconstructed the fossil in three dimensions using VG Studio 3.2. The virtual sections revealed seeds and ovules attached along two lines following the margins of the fruit walls, with some bodies positioned along the upper, adaxial side and others along the lower, abaxial side. This arrangement of multiple enclosed bodies at different developmental stages is central to the team’s case that the organs represent genuine carpels rather than any known gymnospermous structure.

The key diagnostic trait is what botanists call angiospermy, or angio-ovuly: the enclosure of ovules, and ultimately seeds, within a closed organ before pollination. This feature has defined flowering plants since the term angiosperm was coined in 1690 by the German botanist Paul Hermann, and it was the basis on which the celebrated Jurassic fossil Archaefructus liaoningensis was recognized as an early angiosperm in 1998. The presence of both smaller bodies, interpreted as unfertilized ovules or abortive seeds, and larger, seed-coated bodies within the same fruit satisfies both the original and stricter versions of this criterion. The authors acknowledge caveats: some conifers and the seed fern Caytonia do enclose seeds after pollination, but they argue that seed position and overall organ morphology in those groups differ fundamentally from what Permocarpelloides displays.

Beyond the mere presence of enclosed ovules, the orderly, parallel arrangement of the three fruits carries deep evolutionary significance. Because the three structures lie so close together and share the same orientation, the team infers they belonged to a single gynoecium, the female reproductive apparatus of one flower. Their clear separation from one another implies that this gynoecium was apocarpous, meaning it was composed of multiple free, distinct carpels, exactly the condition seen in magnoliids such as magnolias and in the basal angiosperm Amborella. Traditional theories of angiosperm evolution, stretching back to Arber and Parkin’s influential 1907 hypothesis, have held that such free, apocarpous gynoecia were ancestral, making Permocarpelloides the first Permian fossil to match those theoretical expectations so directly.

Yet the fossil also complicates the old textbooks. Classical theory, reinforced by Canright’s 1960 study of magnoliaceous carpels and by the celebrated Cretaceous fossils Archaeanthus and Archaefructus, expects seeds to be borne along the adaxial, upper side of the carpel, reflecting the idea that a carpel is a folded megasporophyll, a seed-bearing leaf. In Permocarpelloides, seeds attach along both sides of the fruit, and the coexistence of seeds at markedly different developmental stages in a single organ is highly unusual. The authors note that ovule position has proven far more variable than the classical model allows: recent work on living Illicium and Michelia, reinvestigation of the Archaeanthus holotype, and studies of the Jurassic fossil Xenofructus all indicate that the placenta may originally have been an ovule-bearing branch independent of any leaf margin, casting doubt on the venerable megasporophyll concept itself.

Permocarpelloides is not an isolated anomaly. It joins a growing roster of putative Early Permian angiosperms from China, including Taiyuanostachya, reported in 2023; Yuzhoua juvenilis, described in 2025; and Dengfengfructus maxima, announced earlier in 2026. Compared with those fossils, Permocarpelloides more closely resembles the carpels of modern flowering plants, thanks to its free carpels and apocarpous organization. The striking morphological diversity among these four distinct Permian fossils suggests that flowering plants were already diversified, and therefore must have originated even earlier than the Asselian stage. The authors argue that the long-standing no-angiosperms-until-Cretaceous belief can no longer accommodate the accumulating evidence and that the standard scenario of angiosperm evolution urgently needs updating.

Independent lines of evidence appear to converge on the same conclusion. Molecular clock analyses, from early amino acid and chloroplast DNA studies in 1989 through recent phylogenomic work in 2024 and 2025, have repeatedly estimated pre-Cretaceous origins for flowering plants, and a 2026 integrated analysis of fossils and molecular divergence times points to a latest Jurassic origin at minimum. Intriguingly, the earliest pollen-loaded insects are known from the Lower Permian of Russia, hinting that insect pollination relationships may have been established far earlier than assumed. Together, the fossil record, the insect record and molecular dating sketch a coherent picture of a long, hidden history of angiosperms stretching back at least 295 million years. Whether Permocarpelloides ultimately proves to be a bona fide angiosperm or an unprecedented gymnosperm exhibiting angio-ovuly, its discovery blurs a boundary botanists have drawn for centuries and is likely to ignite a new wave of debate and discovery in the study of seed plant evolution.

The naming of the new genus itself carries meaning. The prefix Permo- signals the fossil’s surprising age, while the suffix -oides, meaning resembling, reflects the authors’ caution: the organs are only partially preserved, and no complete fruit was recovered. Because ovules and immature seeds are difficult to distinguish even in living plants, the team uses the terms carpel and fruit, and ovule and seed, interchangeably throughout their description, a pragmatic choice that underscores how much interpretation rests on a single specimen.

The preservation context is also instructive. Coal-bearing sequences of the Shanxi Formation have long been worked for economic coal, with Coal No. 4 averaging roughly thirteen meters thick at the Antaibao mine, but such commercial exposures rarely attract attention from palaeobotanists hunting for delicate reproductive structures. That a carpel-like fossil emerged from a siltstone immediately above a major coal seam suggests that similar material may await discovery in museum drawers and mine sections across North China, where the Cathaysian Flora has been documented for decades yet never before yielded organs of this kind.

The non-destructive imaging approach deserves emphasis. Traditional palaeobotany often relies on dégagement, physically chipping away matrix, or on serial sectioning, both of which consume irreplaceable material. Micro-computed tomography at the 26-micrometer scale achieved here allows seeds to be traced to their attachment points on the fruit wall in three dimensions, providing the positional evidence that two-dimensional photographs alone could not deliver. As such scanning becomes routine, comparable fossils from other Permian localities may be re-examined with fresh eyes.

For now, the specimen rests in the type collection under catalogue number PB206132, available for scrutiny by other researchers. The open-access publication ensures that the images and reconstructions can be independently assessed, an important step given how consequential the claim is for one of botany’s most enduring questions.

Subject of Research: Permian carpel-like fossil organs and the pre-Cretaceous origin of angiosperms

Article Title: Permian carpel-like organs and their implications on origin of angiosperms

Article References: Wang, X., Fu, Q., Huang, W., & Sun, J. (2026). Permian carpel-like organs and their implications on origin of angiosperms. Plant Biosystems, 160(5), Article 257. https://doi.org/10.1007/s44473-026-00267-6

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00267-6

Keywords: angiosperm origin, carpel, Permian, Permocarpelloides, fossil, paleobotany, enclosed ovules, apocarpous gynoecium, China, Shanxi Formation, seed plant evolution, Early Permian