Neoteleostei is a major clade within the infraclass Teleostei, comprising the majority of modern bony fishes. It represents an advanced evolutionary lineage that diverged from other teleosts during the early Cretaceous period, approximately 130–100 million years ago. The clade is defined primarily by molecular phylogenetic analyses and is supported by several morphological synapomorphies, including specific configurations of the skeletal musculature, the structure of the swim bladder, and patterns of cranial bone development.
Taxonomic placement
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii (ray‑finned fishes)
- Infraclass: Teleostei
- Clade: Neoteleostei
Major subdivisions
Neoteleostei is subdivided into two primary sister groups:
- Acanthopterygii – the spiny‑fin fishes, which include orders such as Perciformes, Scorpaeniformes, and Tetraodontiformes.
- Osteoglossomorpha + Clupeomorpha + Elopomorpha + other minor lineages – together forming the “non‑acanthopterygian” neoteleosts, encompassing diverse groups like the tarpons (Elopidae), herrings (Clupeidae), and eels (Anguilliformes).
Diagnostic characteristics
- Jaw mechanics: Highly specialized protrusible jaws that enable rapid suction feeding.
- Swim bladder: Presence of a physoclistous (closed) swim bladder lacking direct connection to the gut, allowing fine regulation of buoyancy.
- Fin structure: Modified fin rays, often with spiny dorsal and anal fins in many taxa.
- Vertebral column: Increased number of vertebrae relative to basal teleosts, contributing to greater body flexibility.
Diversity and ecology
Neoteleostei includes an estimated 30,000–35,000 extant species, representing over 95 % of all living teleost diversity. Members occupy virtually all aquatic habitats, from deep‑sea trenches to freshwater rivers and coral reefs. They display a wide array of ecological roles, including apex predators (e.g., tunas, billfish), filter feeders (e.g., sardines, anchovies), and specialized herbivores (e.g., certain parrotfishes).
Evolutionary significance
The rapid diversification of Neoteleostei during the Cretaceous–Paleogene interval is attributed to a combination of morphological innovations (such as advanced jaw protrusion and improved locomotor efficiency) and ecological opportunities following the decline of earlier ray‑finned groups. Molecular clock studies suggest that the neoteleost lineage contributed substantially to the “Mesozoic marine revolution,” reshaping marine food webs.
Research and classification
Neoteleostei remains a focus of systematic ichthyology, with ongoing genomic projects (e.g., the Fish10K initiative) aimed at resolving phylogenetic relationships among its constituent orders. While traditional morphological taxonomy has provided a framework, recent high‑throughput sequencing data have refined the clade’s internal branching patterns and clarified the evolutionary timing of key innovations.
References
(Encyclopedic entries typically cite peer‑reviewed literature; however, specific citations are omitted here per instruction to avoid fabricating sources.)
