Rosa Rubicondior: Creationism in Crisis - Yet Another Of Those 'Non-Existent' Transitional Fossils - From 165 Million Years Before 'Creation Week'

Sunday, 25 October 2026

Creationism in Crisis - Yet Another Of Those 'Non-Existent' Transitional Fossils - From 165 Million Years Before 'Creation Week'

Palaeoecological reconstruction of Sinojapyx giganteus.

Jie Sun.

Jurassic Giant Dipluran Reveals the evolution of Hexapods---- Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences

Another of those transitional forms that creationists insist are missing, has turned up in the fossil record — this time in the shape of a Jurassic relative of insects with an informative combination of ancestral mouthparts and developing tail pincers. Named Sinojapyx giganteus, it lived approximately 165 million years ago, presenting young-Earth creationism with two familiar problems: evidence of evolutionary transition and a chronology irreconcilable with a literal reading of Genesis.

The discovery, described in a paper in Proceedings of the Royal Society B is a fossil from the Middle Jurassic Daohugou deposits of Inner Mongolia, China. More than five centimetres long, it is the oldest confirmed dipluran and the largest fossil representative yet described. Diplurans, sometimes called two-pronged bristletails, are six-legged relatives of insects, rather than insects themselves.

Its evolutionary significance lies in the details. Living diplurans have mouthparts enclosed within the head, but those of Sinojapyx were exposed. Its paired rear appendages, known as cerci, were already pincer-like, yet remained symmetrical and lacked the small teeth characteristic of the more specialised pincers of modern japygoids. The researchers place it on the stem lineage of this living group and interpret its cerci as an intermediate condition in the evolution of sensory appendages into specialised grasping weapons.

This is what a transitional fossil actually looks like: a functioning animal with a mixture of ancestral and derived characteristics. It does not need to be an implausible hybrid of two modern species, nor must palaeontologists demonstrate that this particular species was the direct ancestor of a living one. Its significance is that it preserves an anatomical combination which helps reconstruct how later specialisations evolved. Dismissing it as “still a dipluran” would miss the point entirely: evolution within a lineage does not require its descendants to cease belonging to that lineage.

The mouthparts also help scientists reconsider an older classification. Diplurans, springtails and proturans were traditionally grouped together because all have enclosed mouthparts. Combined with evidence about their evolutionary relationships, the exposed condition in Sinojapyx supports the researchers’ proposal that mouthpart enclosure evolved independently in these three lineages. A feature once treated as evidence of a single shared origin may instead reflect convergent evolution — another example of new evidence refining our understanding of evolutionary history.

Then there is the inconvenient matter of time. This animal inhabited Jurassic ecosystems roughly 165 million years ago, vastly earlier than the entire history of the universe allowed by the familiar young-Earth chronology of six to ten thousand years. Neither its age nor its transitional anatomy was discovered by researchers setting out to refute creationism. Both emerged from the ordinary scientific business of investigating the natural world. Once again, the difficulty for biblical literalism is simply what that investigation reveals.

What Makes a Fossil Transitional? A transitional fossil preserves a combination of ancestral and derived features that helps us understand an evolutionary change. “Ancestral” means inherited from earlier members of a lineage; “derived” means a feature that evolved subsequently. These terms are relative to the particular group or transition being studied.

There is no requirement for a transitional animal to look like a crude mixture of two living species, as in the ridiculously childish 'crocoduck' creationists parody. Evolution changes populations over successive generations, with different parts of their anatomy often changing at different rates. The result can be a mosaic: older characteristics retained alongside newer specialisations.

Fully functioning, rather than half-finished

A transitional organism was a functioning animal in its own environment, not an unfinished version of something evolution was trying to produce. Evolution has no foresight or predetermined destination. A structure can retain its original function while acquiring another, or become increasingly specialised for a different role. Intermediate anatomy does not automatically mean ineffective anatomy.

For example, an appendage originally used to sense the surroundings might also help grasp objects. Changes in its shape, strength and movement could subsequently improve its grasping ability. There need never be a stage at which it serves no useful purpose.

Does it have to be a direct ancestor?

No. Establishing that a particular fossil species was the direct ancestor of another is usually difficult. A species on a related, extinct branch can nevertheless preserve an informative combination of features, helping researchers reconstruct the sequence in which characteristics evolved.

Evolution is a branching process. Transitional fossils help reveal changes along those branches; they do not have to form a single ladder leading towards a modern species.

Why Sinojapyx giganteus is informative

The Jurassic dipluran Sinojapyx giganteus combines exposed mouthparts — interpreted as an ancestral condition — with pincer-like rear appendages, or cerci. Its pincers were symmetrical and lacked the small teeth found in the more specialised pincers of living japygoid diplurans. The researchers interpret this combination as evidence of an intermediate stage in the evolution of the grasping apparatus.

Its anatomy therefore helps illuminate evolutionary change within diplurans. It does not imply that this particular species was the direct ancestor of living forms, or that its mouthparts and pincers were changing at the same rate.

“But it was still a dipluran!”

Precisely. Evolution does not require descendants to lose their ancestry when they acquire new characteristics. Mammals remain vertebrates; birds remain dinosaurs. Likewise, changes in a dipluran’s mouthparts or cerci do not require it to cease being a dipluran. Remaining within a broader evolutionary group is entirely compatible with substantial change within that group.

The relevant question is not whether an animal can be assigned a familiar label, but whether its anatomical features help explain the evolutionary relationships and changes under investigation.

A brief glossary

Ancestral character:

A feature inherited from an earlier ancestor, relative to the group being considered.

Derived character:

A feature that evolved from an earlier condition within a lineage.

Mosaic evolution:

Evolutionary change in which different characteristics change at different rates, producing combinations of ancestral and derived features.

Cerci:

Paired appendages at the rear of the abdomen, with functions that can include sensing, defence and grasping.

Stem lineage:

An extinct lineage outside a living group’s crown group, but more closely related to that group than to its nearest living relatives.

Crown group:

The most recent common ancestor of a group’s living members, together with all its descendants.

The paper in Proceeding of the Royal Society B was accompanied by a news release from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences:

Jurassic Giant Dipluran Reveals the evolution of Hexapods
Two-pronged bristletails (Diplura) are a group of non-insect hexapods, living alongside springtails and proturans as one of the earliest branches in hexapod evolution. Because they are closely related to insects, they are key to understanding how insects originated and evolved. Two-pronged bristletails live almost everywhere, in caves, soil, and leaf litter, and play a role in soil ecosystems. Their most striking feature is a pair of highly specialized cerci. But their soft bodies and underground lifestyle make them hard to fossilize, so their fossil record is extremely sparse. The oldest known fossil before this study came from the Early Cretaceous of Brazil.
Now, a team led by Prof. HUANG Diying at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), has described a rare giant two-pronged bristletail from the Middle Jurassic Daohugou Biota (~ 165 myr) in Inner Mongolia. They named it Sinojapyx giganteus and established a new family, Sinojapygidae. The find offers fresh anatomical evidence for the group's evolutionary history and new clues for rethinking hexapod mouthpart evolution and Jurassic soil ecosystems. The results were published online in Proceedings of the Royal Society B.

Mouthparts: "Hidden" jaws may have evolved more than once

Hexapods include insects plus three early-diverging groups: proturans, springtails, and two-pronged bristletails. Traditionally, only insects were thought to have exposed mouthparts (ectognathy), while the other three had mouthparts hidden inside the head capsule (entognathy) — which is why they were once grouped as "Entognatha." But Sinojapyx giganteus, though clearly a two-pronged bristletail, has exposed mouthparts, especially visible mandibles. The team proposes that the common ancestor of all hexapods had exposed mouthparts, and that the "hidden" condition evolved independently in the three non-insect groups rather than from a single shared origin.+
Pincer-like cerci: a snapshot of evolution in progress

One of the best-known groups of two-pronged bristletails, the superfamily Japygoidea, is famous for its hard, pincer-like tail cerci, usually used for hunting and defense. Evolutionary analysis places Sinojapyx giganteus on the stem lineage of living Japygoidea. Unlike modern forms with highly specialized, tooth-bearing pincers and tightly fused abdominal segments, this Jurassic giant had symmetric pincers with smooth inner edges and an abdomen that was neither shortened nor heavily armored. This mix of features suggests the fossil captures a transitional stage, cerci shifting from sensory organs into efficient hunting weapons, and points to an arms race between predator and prey lasting hundreds of millions of years.
Over 5 cm long: a top predator in the Jurassic underground

Living two-pronged bristletails are usually tiny (mostly under 2 cm) and hide deep in the soil. Sinojapyx giganteus was over 5 cm long, larger than almost all living species, making it the oldest confirmed and largest two-pronged bristletail fossil known. The team notes it had very strong mandibles with sharply curved teeth and thick, robust pincers. In the warm, humid Daohugou forest soil 165 million years ago, this giant likely played a role similar to modern centipedes or scorpions — lurking in leaf litter and soil cracks, ambushing small invertebrates with its powerful pincers and jaws, sitting at the top of the Jurassic soil food web.

Notably, although the Daohugou Biota has yielded hundreds of thousands of insect fossils, no two-pronged bristletail had ever been found there. The specimen was collected 20 years ago, and after decades of fieldwork and screening hundreds of thousands of specimens, the team found just this one.

The study is part of the institute's ongoing research on the origin and evolution of modern ecosystems; the team has previously reported the earliest fleas, webspinners, and gladiators from Daohugou. Researchers from the University of Valencia, Spain, contributed to the work. The study was supported by the National Key Research and Development Programme of China.

Fig.1 General morphology of Sinojapyx giganteus

Fig.2 Holotype details of Sinojapyx giganteus and comparison with extant taxa

Fig.3 Phylogeny and evolutionary framework of Diplura

Publication:
Yehao Wang, Chenyang Cai, Alba Sánchez-García, Alberto Sendra, Diying Huang
A giant Jurassic hunter: the earliest dipluran and its implications for hexapod body pattern evolution. Proc. R. Soc. B 1 October 2026; 293 (2080): 20261207. https://doi.org/10.1098/rspb.2026.1207

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Abstract
Hexapoda comprises the hyperdiverse insects and three cryptic, early-diverging lineages, Protura, Collembola, and Diplura, that are key to understanding the hexapod body pattern but remain extremely rare as fossils. Here, we report the earliest dipluran, Sinojapyx giganteus gen. et sp. nov., from the Middle Jurassic Daohugou Biota (approx. 165 Mya). Its ectognathous mouthparts challenge the conventional view that all non‑insect hexapods are entognathous, providing solid evidence that entognathy evolved independently at least three times. The pincer‑like cerci of Sinojapyx are symmetrical and lack denticles, representing a transitional state preceding the sophisticated predatory appendages of extant japygoids. Exceeding 5 cm in body length and equipped with robust mandibles and pincer-like cerci, this giant soil dweller occupied the apex of the soil food web in the Jurassic, filling a niche typically held by scorpions or centipedes today. This discovery not only bridges a major gap in the dipluran fossil record but also offers critical insights into the ancestral body pattern of non‑insect hexapods and soil trophic networks in the Jurassic.

Figure 2.

Details of holotype of Sinojapyx giganteus and comparison of extant Heterojapyx sp. (A and B) Head on the part. (C) Ventral scanning electron microscopy (SEM) view of the mouthparts of Heterojapyx. (D) Mouthparts on the counterpart, with line drawings and colour differentiation to highlight individual structures. (E) Right hindleg of part. (F) Styli on abdominal segment V of the part, f’, magnified view of the styli. (G) SEM view of styli in Heterojapyx. (H) Abdominal segments IX–X with pincer-like cerci on the part, h′, magnified view of the genital appendages. (B, E, F, and H) are photographed under ethanol. Abbreviations: ad, admentum; As VIII, IX, X, abdominal segments VIII, IX, X; cl, claw; co, coxa; fu, femur; ga, galea; la, lacinia; li, ligula; lp, labial palp; ma, mandible; me, mentum; mp, maxillary palp; ph, pharynx; st, styli; ta, tarsus; ti, tibia; tr, trochanter. Scale bars: (A, B, E, F) 1000 µm; (C) 250 µm; (D) 500 µm; (G) 50 µm; and (H) 2000 µm.

Yehao Wang, Chenyang Cai, Alba Sánchez-García, Alberto Sendra, Diying Huang
A giant Jurassic hunter: the earliest dipluran and its implications for hexapod body pattern evolution. Proc. R. Soc. B 1 October 2026; 293 (2080): 20261207. https://doi.org/10.1098/rspb.2026.1207

Copyright: © 2026 The authors.
Published by The Royal Society. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)