Amazing stuff! What a story! Poop with scales!
"Nearly 250 million years ago in what is now northwestern Argentina, a hippo-sized herbivore lumbered about and gobbled up all sorts of plants, along with any fungi, insects, and other critters that were coincidentally mixed in among the green. Eventually that creature defecated, leaving behind a mound of poop that happened to fossilize—and preserve what an analysis now reveals is the oldest ever evidence of butterflies and moths.
The fossilized piece of poop, known as a coprolite, was found in a 236-million-year-old “communal latrine” at Argentina’s Talampaya National Park, where now-extinct herbivores called dicynodonts engaged in social behavior by effectively creating prehistoric restrooms. While analyzing these coprolites’ contents, researchers found that one of them contained ornate, microscopic scales like the ones on the wings of lepidopterans, the group of insects that contains butterflies and moths.
The discovery helps plug a nagging hole in the evolutionary story of lepidopterans. Family trees based on genetic data had suggested that lepidopterans arose around 241 million years ago. But until the Argentine coprolite scales, the oldest known lepidopteran fossils—wing scales found in sediments in Germany—were only 201 million years old.
The find also implies that butterflies and moths with probosces, those straw-like structures perfect for slurping up nectar, likely evolved between 260 and 244 million years ago. Early probosces may have given early lepidopterans an edge in eating conifers’ sugary secretions—while also setting them up to co-evolve with flowers, which wouldn’t appear for another 100 million years.
In addition, the coprolite’s butterfly scales are so unlike any others found previously that paleontologists have used them to name a new butterfly species: Ampatiri eloisae.
The name honors Eloísa Argañaraz, a doctoral student who died from brain cancer months after co-discovering the coprolites.
It also pays tribute to the Calchaquí Indigenous peoples, who live in the area where the fossil dung was found. In the Calchaquí language, Kakán, ámpa means butterfly, and tiri means ancient. In their worldview, when a warrior dies, their soul becomes a butterfly or journeys on its wings."
From the highlights and abstract:
"Highlights
• After end-Permian mass extinction, the Triassic witnessed a super-radiation of modern insects (i.e., hymenopterans, dipterans, and lepidopterans).
• We report the oldest known record of hexapod scales, which were recovered from a megaherbivore dicynodont coprolite.
• The coprolite comes from a communal latrine in lower Carnian deposits (∼236 Ma) of the Chañares Formation, NW Argentina.
• The unique combination of features (e.g., ornamented hollow scales with internal lumen) suggests lepidopteran affinities.
• The Chañares scales contribute to the temporal mismatch between phylogenomic and fossil evidence of lepidopterans.
Abstract
Life on Earth nearly came to an end during the end-Permian mass extinction (EPME; c. 252 Ma). In its aftermath, the Triassic witnessed the adaptation of survivors to a postapocalyptic world and the establishment of modern ecosystems. Inland, these changes included an outstanding turnover between amniote groups triggered by the diversification of plants and arthropods. A super-radiation of morphologically modern insects occurred in the Triassic, including some of their most successful and ecologically relevant groups, such as Diptera (flies and mosquitoes) and Lepidoptera (moths and butterflies).
Here, we describe the oldest evidence of hexapod scales, preserved within a megaherbivorous kannemeyeriiform dicynodont coprolite. This specimen comes from a communal latrine in the lower Carnian deposits (∼236 Ma) of the Chañares Formation, La Rioja Province, northwestern Argentina. The tiny fossil scales are hollow and ornamented, which is a synapomorphy of Lepidoptera and suggests that they could belong to this group. If this is the case, the Chañares scales would partially fill the temporal mismatch between phylogenomic date and the fossil evidence of butterflies and moths because they preceded the previously oldest lepidopteran record by c. 35 million years.
Moreover, the scales have a combination of features present in early diverging glossatan lepidopterans. The inclusion of the temporal data provided by the Chañares scales into an updated temporal calibration of lepidopteran phylogeny shows that the proboscis, a key evolutionary novelty for the group (Glossata), evolved between c. 260–244 Ma. Thus, the proboscis-bearing lepidopterans would be part of the repertory of new plants and animals that diversified during the aftermath of the EPME."
ScienceAdviser
Preserved in a 236-million-year-old piece of fossilized dung, these microscopic wing scales—each less than 200 microns long—are distinctive enough that paleontologists used them to name a species of extinct butterfly, Ampatiri eloisae.
