Tertius News is an AI-native newsroom: an AI model reads the linked source articles below and extracts what each outlet reported, so you can compare their coverage side by side. How this works →

New information became available — this story may be updated shortly.

Amphibious Insect Fossil from 324 Million Years Ago Illuminates Land Transition

Researchers have identified a 324-million-year-old stem insect, Chosha praecursor, from Texas, suggesting insects underwent a prolonged amphibious phase before fully conquering land. The study, published in Nature, provides direct fossil evidence that the shift from water to land was gradual.

By Tertius News AI Desk 3 outlets · 2 distinct · 3 articles Version 1 Coverage Aug 27, 2026 Published 16h ago

An international team of researchers has identified a stem group insect from the Late Mississippian period, about 324 million years ago. The discovery, published in Nature on August 26, offers new insight into how insects made the transition from water to land, suggesting a long amphibious phase rather than a sudden shift.

The research was led by Prof. Chenyang Cai of the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS) and Erik Tihelka, a joint training Ph.D. student at the University of Cambridge. Collaborators from the United States, Spain, and other countries also contributed to the study.

A New Species from the Late Mississippian

The researchers describe a new species, Chosha praecursor, found in calcareous claystone concretions in the Tesnus Formation of the Marathon Uplift in western Texas. The specimens are adult female insects, not crustacean larvae as originally classified. Their bodies measure 32.09 millimeters long, and with the median caudal filament and two cerci, they reach a total length of 49.66 millimeters. These insects possessed an ovipositor, a terminal caudal filament, a segmented trunk, six walking legs, and abdominal appendages modified into paddle-like structures.

In addition to the new species, the researchers reevaluated three other enigmatic Paleozoic hexapods: Loverhulmia from the Early Devonian of Scotland and an unnamed hexapod from the Mazon Creek biota in Illinois, USA. They concluded that all three belonged to a primitive stem lineage of insects.

Filling the Gap in the Fossil Record

Undisputed hexapod body fossils first appear in the Early Devonian Rhynie Chert around 405 million years ago. However, clearly recognizable insect fossils do not become abundant until the Late Carboniferous, leaving an approximately 80-million-year gap. The discovery of C. praecursor, which sits in this gap, helps fill that void.

The findings suggest that insects did not become fully land-dwelling immediately. Instead, early forms retained and modified features inherited from aquatic ancestors, spending a prolonged period in an amphibious, semi-aquatic lifestyle. This supports the idea that an amphibious stage was a crucial bridge between fully aquatic and completely terrestrial environments.

The specimens provide direct fossil evidence that the evolution from water to land occurred gradually over an extended evolutionary process, challenging long-standing ideas about the insect body plan's development and offering a clearer picture of how pancrustacean ancestors transitioned onto land.

How each outlet told it

Mirage News as of Aug 27, 2026, 3:46 AM UTC

Framing: The headline emphasizes the discovery's contribution to understanding insect land colonization, highlighting the new fossil's role as an 'amphibious stem-insect' and the resulting insight into the 'land shift'. — celebratory

Facts Included:

An international research team discovered a new stem-group insect from the Late Mississippian period, approximately 324 million years ago.
The study was led by Prof. CAI Chenyang from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and Erik Tihelka, a joint Ph.D. student at the University of Cambridge, with collaborators from the US and other countries.
The findings were published in Nature on August 26.
The new species is named Chosha praecursor.
The fossils were recovered from calcareous claystone concretions in the Tesnus Formation of the Marathon Uplift in western Texas.
C. praecursor had an ovipositor, a terminal caudal filament, a segmented trunk, six walking legs, and segments 1-9 of the abdomen bore appendages, with posterior abdominal limbs modified into paddle-like structures.
The fossils measured 32.09 millimeters in body length (49.66 mm including the caudal filament).
The researchers reassessed three Paleozoic hexapod fossils: Leverhulmia from the Early Devonian of Scotland, an unnamed hexapod from the Mazon Creek biota of Illinois, and C. praecursor.
The study suggests early insects passed through a semi-aquatic, amphibious phase and that the colonization of land by insects was gradual.
The researchers reconstructed ecological scenarios, suggesting early insects' diets included humus, plant detritus, and fungal spores, and they acted as decomposers and consumers in aquatic-terrestrial ecotones.

Read the source article →

Phys.org as of Aug 27, 2026, 11:46 PM UTC

Framing: The headline emphasizes the discovery's significance for understanding insect evolution, highlighting the retention of aquatic limbs during the transition to land. — informative

Facts Included:

A new stem-group insect from the Late Mississippian period, approximately 324 million years ago, was discovered.
The species is named C. praecursor.
C. praecursor had an ovipositor, a terminal caudal filament, a segmented trunk, and six walking legs.
Segments 1–9 of the abdomen bore segmented appendages, with the posterior abdominal limbs modified into paddle-like structures.
The fossils were recovered from calcareous claystone concretions in the Tesnus Formation of the Marathon Uplift in western Texas.
The study was led by Professor CAI Chenyang from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS) and Erik Tihelka, a joint-training Ph.D. student at the University of Cambridge, with collaborators from the United States, Spain and other countries.
The research was published in Nature.
Researchers also investigated enigmatic stem-insect material from the Early Devonian chert biota of Britain and the Late Carboniferous Mazon Creek biota of the United States.
Molecular-clock reconstructions suggest hexapods diverged from marine crustacean relatives and began adapting to land as early as the Cambrian–Ordovician interval, but undisputed hexapod body fossils appear in the Early Devonian Rhynie Chert about 405 million years ago.
The new fossils suggest the reduction of abdominal appendages was a key evolutionary innovation for terrestrial adaptation, with these structures progressively simplified as swimming appendages of crustacean ancestors were lost.
The ovipositor preserved in C. praecursor indicates early insects already possessed diverse oviposition adaptations.
Stem-group insects combined aquatic locomotor and respiratory adaptations with terrestrial body architectures, and their diets likely included humus, plant detritus and fungal spores.
The fossils challenge interpretations of body size evolution, ecological adaptation and coevolution with terrestrial ecosystems.

Read the source article →

ScienceDaily as of Aug 27, 2026, 8:46 AM UTC

Framing: Emphasizes the fossil's revelation about insect terrestrialization, focusing on the scientific discovery and its evolutionary significance. — informative and neutral

Facts Included:

An international team of researchers has identified a stem group insect from the Late Mississippian period, about 324 million years ago.
The research was led by Prof. Chenyang Cai of the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS) and Erik Tihelka, a joint training Ph.D. student at the University of Cambridge.
The findings were published in Nature on August 26.
The researchers describe a new species called Chosha praecursor.
The fossils were found in calcareous claystone concretions in the Tesnus Formation of the Marathon Uplift in western Texas.
Using cross-polarized light imaging, the researchers identified distinctive features that revealed the fossils had been misclassified for years.
The specimens were adult female insects, not crustacean larvae.
The bodies measured 32.09 millimeters long; with median caudal filament and two cerci, total length reached 49.66 millimeters.
C. praecursor possessed an ovipositor, a segmented trunk, and six walking legs.
Segments 1 through 9 carried segmented appendages, and rear abdominal limbs were modified into paddle-like structures.
Geological reconstructions indicate the sediments formed in near-shore, shallow-water delta coastal environments.
The team reevaluated three Paleozoic hexapods: Leverhulmia from the Early Devonian of Scotland, an unnamed hexapod from the Mazon Creek biota of Illinois, and C. praecursor.
The researchers concluded that all three belonged to a primitive stem lineage of insects.
The findings push the early diversification of insects back from the Late Carboniferous into the Early Devonian, bringing the fossil record closer to molecular clock estimates.
Stem group insects appear to have combined aquatic adaptations with body structures suited to land, probably feeding on humus, decaying plant material, and fungal spores.

Read the source article →

Transparency & Audit Trail

1 outlet · 1 article consulted: ScienceDaily 16 claims extracted Version 1 Written 2026-08-27