Tag: eocene

Tiny beetle trapped in 53-million-year-old amber is named after Twenty One Pilots

Scientists use a synchrotron to reveal the first formally described puppet beetle from France’s Oise amber.

Preserved in amber for about 53 million years, a beetle has been described as a new species by researchers in Spain and France. Named Cnopus twentyonepilotorum, it is the first puppet beetle (family Aderidae) to be formally described from the Oise amber of northern France. The findings are published in the open-access journal ZooKeys.

The study was led by Jules Ferreira, a PhD candidate at the Institut Botànic de Barcelona (CSIC-CMCNB) and the Facultat de Ciències de la Terra of the Universitat de Barcelona, with Erich L. Spiessberger and David Peris. They worked with André Nel of the Institut de Systématique, Évolution, Biodiversité (ISYEB) at the Muséum national d’Histoire naturelle in Paris, a joint unit of the CNRS, Sorbonne Université, EPHE and Université des Antilles, and with Alessandra Patera of the ALBA Synchrotron.

†Cnopus twentyonepilotorum sp. nov., holotype C05038. Habitus of the holotype in dorsal view. Scale bars: 250 µm. Credit: Ferreira et al. 2026, ZooKeys.

Puppet beetles, also known as ant-like leaf beetles, are small insects with about 1,000 living species found on every continent except Antarctica. Despite this reach, their biology is poorly known and their fossil record is sparse. The Oise amber, from Le Quesnoy near Creil, is one of the oldest Cenozoic ambers in Europe and preserves the fauna of a warm, humid forest from the early Eocene.

“Aderidae had already been reported from this amber, but none had ever been formally described. Our specimen offered the opportunity to fill this gap and to better understand the evolutionary history of the family.”

– Jules Ferreira

To study the fossil without damaging the amber, the team used synchrotron X-ray microtomography at the ALBA Synchrotron, which allowed them to reconstruct a detailed 3D model of the fossil beetle and compare it with living species. The beetle belongs to Cnopus, a genus that still exists today. Until now, its oldest fossils of this genus came from the Baltic and Bitterfeld ambers, around 38 to 34-million-years-old.

†Cnopus twentyonepilotorum sp. nov., holotype C05038. 3D renderings. Credit: Ferreira et al. 2026, ZooKeys.

This discovery shows that this beetle lineage was already established in Western European forests in the early Eocene, roughly 15 million years earlier than previously documented. Some internal structures normally used to distinguish living species were not preserved, so the fossil cannot be fully compared with all its modern relatives. Its age, however, makes it very unlikely to belong to a species still alive today.

“What surprised us most was how little the external morphology of this lineage has changed over time. Despite more than 50 million years of evolution, major climatic changes and the transformation of European forests, the overall external morphology of these tiny beetles has remained remarkably stable.”

– Jules Ferreira

The species name honours the band Twenty One Pilots. The authors say the dedication acknowledges the group’s contribution to raising awareness of mental health and to reducing the stigma around anxiety, depression and personal hardship.

The team is now studying other puppet beetles from the Oise amber and hopes to learn which beetle groups persisted in European forests between the early and late Eocene.

“Amber is exceptional in this respect. It sometimes preserves several organisms trapped together, offering rare snapshots of ancient ecological associations. Each new fossil adds a piece to this puzzle and helps us better understand how beetle communities were assembled and how they changed through time.”

– Jules Ferreira

The holotype is held in the palaeontological collection of the Muséum national d’Histoire naturelle in Paris.

Original source:

Ferreira J, Spiessberger EL, Nel A, Patera A, Peris D (2026) First fossil species of puppet beetles (Coleoptera, Tenebrionoidea, Aderidae) from the lowermost Eocene Oise amber (France), with a review of the fossil record of Aderidae. ZooKeys 1297: 153-180. https://doi.org/10.3897/zookeys.1297.210120

For more articles on zoology, visit the ZooKeys website and follow the journal on BlueSky and Facebook.

“Oldest bamboo” fossil from Eocene Patagonia turns out to be a conifer

A recent examination revealed that Chusquea oxyphylla, a fossilised leafy branch from the early Eocene in Patagonia, which has been widely cited as the oldest bamboo fossil and as evidence for a Gondwanan origin of bamboos is actually a conifer. The results of the finding are published in the open-access journal Phytokeys.

A fossilised leafy branch from the early Eocene in Patagonia described in 1941 is still often cited as the oldest bamboo fossil and the main fossil evidence for a Gondwanan origin of bamboos. However, a recent examination by Dr. Peter Wilf from Pennsylvania State University revealed the real nature of Chusquea oxyphylla. The recent findings, published in the paper in the open-access journal Phytokeys, show that it is actually a conifer.  

The corrected identification is significant because the fossil in question was the only bamboo macrofossil still considered from the ancient southern supercontinent of Gondwana. The oldest microfossil evidence for bamboo in the Northern Hemisphere belongs to the Middle Eocene, while other South American fossils are not older than Pliocene. 

Over the last decades, some authors have doubted whether the Patagonian fossil was really a bamboo or even a grass species at all. But despite its general significance, modern-day re-examinations of the original specimen were never published. Most scientists referring to it had a chance to study only a photograph found in the original publication from 1941 by the famous Argentine botanists Joaquín Frenguelli and Lorenzo Parodi.

In his recent study of the holotype specimen at Museo de La Plata, Argentina, Dr. Peter Wilf revealed that the fossil does not resemble members of the Chusquea genus or any other bamboo.

“There is no evidence of bamboo-type nodes, sheaths or ligules. Areas that may resemble any bamboo features consist only of the broken departure points of leaf bases diverging from the twig. The decurrent, extensively clasping leaves are quite unlike the characteristically pseudopetiolate leaves of bamboos, and the heterofacially twisted free-leaf bases do not occur in any bamboo or grass,” wrote Dr. Wilf.

Instead, Wilf linked the holotype to the recently described fossils of the conifer genus Retrophyllum from the same fossil site, the prolific Laguna del Hunco fossil lake-beds in Chubut Province, Argentina. It matches precisely the distichous fossil foliage form of Retrophyllum spiralifolium, which was described based on a large set of data – a suite of 82 specimens collected from both Laguna del Hunco and the early middle Eocene Río Pichileufú site in Río Negro Province. 

Retrophyllum is a genus of six living species of rainforest conifers. Its habitat lies in both the Neotropics and the tropical West Pacific.

The gathered evidence firmly confirms that Chusquea oxyphylla has nothing in common with bamboos. Thus, it requires renaming.  Preserving the priority of the older name, Wilf combined Chusquea oxyphylla and Retrophyllum spiralifolium into Retrophyllum oxyphyllum.

The exclusion of a living New World bamboo genus from the overall floral list for Eocene Patagonia weakens the New World biogeographic signal of the late-Gondwanan vegetation of South America, which already showed much stronger links to living floras of the tropical West Pacific.

“The strongest New World signal remaining in Eocene Patagonia based on well-described macrofossils comes from fossil fruits of Physalis (a genus of flowering plants including tomatillos and ground cherries), which is an entirely American genus,” concludes Dr. Wilf.

Original source:
Wilf P (2020) Eocene “Chusquea” fossil from Patagonia is a conifer, not a bamboo. PhytoKeys 139: 77-89.
https://doi.org/10.3897/phytokeys.139.48717