# A new early actinopterygian from the Mid-Pennsylvanian Logan Quarry Shale member of Indiana

**Authors:** Chenchen Shen, Giorgio Carnevale, Giorgio Carnevale, Giorgio Carnevale

PMC · DOI: 10.1371/journal.pone.0320932 · 2025-05-07

## TL;DR

A new species of early ray-finned fish, Kalops loganensis, is discovered in Indiana, expanding the known range and survival timeline of the Kalops genus.

## Contribution

The discovery of Kalops loganensis provides the first record of Kalops outside of Bear Gulch and confirms its survival into the Mid-Pennsylvanian.

## Key findings

- Kalops loganensis is a new species of Kalops found in the Moscovian Logan Quarry Shales of Indiana.
- Phylogenetic analysis shows Kalops is a basal Actinopterygii and sister to other Bear Gulch genera.
- The species confirms Kalops' presence in North America during the Mid-Pennsylvanian.

## Abstract

Kalops is a genus of early ray-finned fish in North America. It is distinguished from early actinopterygians by the combination of the following characters: subterminal mouth, rounded oval shaped lacrimal, multiple small supraorbitals and suborbitals. So far, it has been only excavated from the Serpukhovian (Late Mississippian) Bear Gulch Limestone in Montana. Here, a new species of this genus, Kalops loganensis n. sp., is described based on two specimens from the Moscovian Logan Quarry Shales in Indiana. The phylogenetic analysis indicates that the new species is a member of Kalops and recovered as the sister of the other two species, and the genus is recovered as a basal Actinopterygii, as the sister group of some other genera from the Bear Gulch Limestone. This new species is the first record of Kalops outside of Bear Gulch. It provides evidence of survivability of this genus, and as the youngest member, proves that Kalops lived at least through the Mid-Pennsylvanian in North America.

## Full-text entities

- **Diseases:** K. diophrys (MESH:D014813), GUID (MESH:D001037), NAMS (MESH:D001759), LSID (MESH:D003643), FMNH (MESH:D012893)
- **Chemicals:** ammonium chloride (MESH:D000643), -D-24-33140A (-), ganoine (MESH:C067951), water (MESH:D014867)
- **Species:** Actinopterygii (fishes, superclass) [taxon 7898], Homo sapiens (human, species) [taxon 9606]
- **Mutations:** M205C
- **Cell lines:** FMNH PF-5919 — Meleagris gallopavo (Wild turkey), Finite cell line (CVCL_0I61), FMNH — Rattus norvegicus (Rat), Rat large granular lymphocyte leukemia, Cancer cell line (CVCL_F856), FMNH PF-2286 — Homo sapiens (Human), Lung adenocarcinoma, Cancer cell line (CVCL_1545)

## Figures

18 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12057928/full.md

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Source: https://tomesphere.com/paper/PMC12057928