Proexochokefalos
extinct genus of reptiles
Proexochokefalos (meaning "big head with big tuberosities") is an extinct genus of machimosaurid teleosauroid from the Middle to Late Jurassic of France and Switzerland. In life, it was a large marine reptile that would have fed on other large animals.
History
The type species, P. heberti, was originally named "Steneosaurus" heberti by Morel de Glasville in 1876 from a roughly 1.1 meter (3.6 foot) long complete skull and mandible (MNHN.F 1890-13) found in the Callovian aged Marnes de Dives near Villers-sur-mer in the Calvados department of Normandy, France. The genus Steneosaurus was used as a longtime wastebasket taxon for various teleosauroid specimens and had more than a dozen species. The type species, Steneosaurus rostromajor is undiagnostic, making the genus and species dubious and invalid. Additionally, many species of so called "Steneosaurus" were found to be quite different and unrelated to one another, thus needing new generic names.
In a study by Michela Johnson and colleagues in 2020, "Steneosaurus" heberti was reclassified into the new genus Proexochokefalos, resulting in the new combination Proexochokefalos heberti. The species "Steneosaurus" depressus was also found to be a junior synonym of P. heberti. Another species referred to the genus, Proexochokefalos cf. bouchardi is known from remains from the Calcaire de Caen, France, and Reuchenette Formation, Switzerland.
The public source identifies “Proexochokefalos” as extinct genus of reptiles. This brief keeps that definition visible, then builds a research path around Proexochokefalos, extinct and genus.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Proexochokefalos”, the useful work is to connect “extinct genus of reptiles” to the records capable of establishing context and consequence.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Aug 31, 2026. The linked authority identifier is Q90545440. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1876, 1890 and 2020.
Current terminology should not be projected backward without checking the classification used when the underlying evidence was created. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
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Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
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- Expand the search: follow Proexochokefalos primary sources, Proexochokefalos archive and Proexochokefalos research across catalogues and specialist indexes.
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Questions for further research
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This entry incorporates text from “Proexochokefalos” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.