Leolepis: a little Permian fish closer to Pteronisculus

Gallo et al 2026 bring us a description of
Leolepis (Fig 1), which they describe as “the first articulated Paleozoic ray-finned fish from the late Permian of the Paran ́a Basin. The nearly complete fish fossil reaching of about 150 mm maximum length is a rare find. Its body is fusiform, covered by at least 50 longitudinal rows of thin ganoid scales with serrated posterior margins. A systematic analysis of Leolepis gen. nov. within the phylogeny of actinopterygians resolved it as the sister-genus to Paramblypterus, with Angatubichthys positioned as a basal member of the group (Angatubichthys + (Paramblypterus + Leolepis)).”

Those taxa are shown to scale here (Fig 1), along with Earl to Middle Triassic Pteronisculus, a taxon not mentioned in the authors’ text.

Here
in the large reptile tree (LRT, 2340 taxa) Angatubichthys and Paramblypterus have not been tested – but Pteronisculus (Figs 1, 2) is a sister to Leolepis in the LRT.

It’s not immediately apparent, given the two views of the skull (Fig 2). DGS helps.

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It’s been awhile since
a new fish entered the LRT, so I had to warm up to this one. The fish subset of the LRT includes 506 taxa and is well-resolved down to 3 MPTs.

Wish the mammals were that easy.

The dorsal view preservation
of Leolepis is usually found in taxa with a skull twice as wide as tall. That does not seem to be the case here, as the torso is not that wide (Fig 1) and sister taxa with a similar morphology do not have a low, wide skull. Leolepis was crushed from above, but not by the asteroid.

Much of the publicity plays up
the fish’s proximity to a coeval asteroid crater in Southern Brazil.

Highlights
• A new and well-preserved fossil ray-finned fish (Actinoppterygii) is described from the State of Mato Grosso
• Leolepis matogrossensis gen. et sp. nov., comes from the Corumbataí Formation, late Permian of the Paraná Basin.
• The single specimen was discovered in a reddish siltstone originated in a shallow megalake.
• The fossiliferous outcrop is located only 50 km from the largest impact crater in South America.
• There is evidence that the rock sequence comes from is close in age of that event.

References
Gallo et al (5 co-authors) 2026. Leolepis matogrossensis gen. et sp. nov., an upper Permian actinopterygian fish from the Corumbataí Formation, in the vicinity of the Araguainha impact crater, State of Mato Grosso, mid-Western Brazil 1-s2.0-S0895981126002282-main.pdf

wiki/Paramblypterus
too soon for its own Wikipedia page/Leolepis

Publicity
https://www.nhm.ac.uk/press-office/press-releases/ancient-armoured-fish-that-narrowly-avoided-meteorite-strike-rev.html

https://www.nhm.ac.uk/press-office/press-releases/ancient-armoured-fish-that-narrowly-avoided-meteorite-strike-rev.html

Source: https://pterosaurheresies.wordpress.com/2026/08/11/leolepis-a-little-permian-fish-closer-to-pteronisculus/