Triconodon fossil map
Where fossils of Triconodon have been found, shown on the Earth as it looked about 145 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 145 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →

| Group | Early mammals |
|---|---|
| Lived | 143.1–137.05 million years ago (Berriasian) |
| Periods | Cretaceous |
| Family | Triconodontidae |
| Named by | Owen 1859 |
| Fossil records | 12 occurrences at 3 locations (PBDB) |
| Found in | United Kingdom, France |
| Rock formations | Lulworth, txn:39760 |
About Triconodon
Triconodon ("three-coned tooth") is a genus of extinct mammal from the Early Cretaceous of England and France with two known species: T. mordax and T. averianovi. First described in 1859 by Richard Owen, it is the type genus for the order Triconodonta, a group of mammals characterised by their three-cusped (triconodont) molar teeth. Since then, this "simplistic" type of dentition has been understood to be either ancestral for mammals or else to have evolved multiple times, rendering "triconodonts" a paraphyletic or polyphyletic assemblage respectively, but several lineages of "triconodont" mammals do form a natural, monophyletic group, known as Eutriconodonta, of which Triconodon is indeed part of.
Triconodon, therefore, is significant in the understanding of the evolution of mammals by originating the understanding of the "triconodont" grade and eutriconodont clade. Further discoveries on its skeletal anatomy also offer further insights on the palaeobiology of Mesozoic mammals.
Text in “About” is quoted from the Wikipedia article Triconodon (revision 1373253746), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 23 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q778777.