Megaconus fossil map
Where fossils of Megaconus have been found, shown on the Earth as it looked about 160 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 160 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 | 165.3–161.5 million years ago (Callovian) |
| Periods | Jurassic |
| Family | Kermackodontidae |
| Named by | Zhou et al. 2013 |
| Fossil records | 2 occurrences at 1 locations (PBDB) |
| Found in | China |
| Rock formations | Tiaojishan |
About Megaconus
Megaconus is an extinct genus of allotherian mammal from the Middle Jurassic Tiaojishan Formation of Inner Mongolia, China. The type and only species, Megaconus mammaliaformis was first described in the journal Nature in 2013. Megaconus is thought to have been a herbivore that lived on the ground, having a similar posture to modern-day armadillos and rock hyraxes. Megaconus was in its initial description found to be member of a group called Haramiyida. A phylogenetic analysis published along its description suggested that haramiyidans originated before the appearance of true mammals, but in contrast, the later description of the haramiyidan Arboroharamiya in the same issue of Nature indicated that haramyidans were true mammals.
If haramiyidans are not mammals, Megaconus would be one of the most basal ("primitive") mammaliaforms to possess fur, and an indicator that fur evolved in the ancestors of mammals and not the mammals themselves. However, later studies cast doubt on the euharamiyidan interpretation, instead finding it to be a basal allotherian mammal. Based on the melanosomes preserved in its fur, Megaconus likely had a uniformly dark-brown coloration, similar to that of other early mammaliaforms including Arboroharamiya and Vilevolodon.
Text in “About” is quoted from the Wikipedia article Megaconus (revision 1376526933), 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: Q15220921.
