{{Infobox rockunit | name = Mae Long Formation | image = | caption = | type = Geological formation | age = Early Miocene (MN 4)<br>~{{fossil range|18}} | period = Burdigalian | prilithology = Sandstone | otherlithology = | namedfor = | year_ts = | namedby = | region = Lamphun Province | country = Thailand | coordinates = <!--{{coord|16.3|N|102.0|E|display=inline,title}}--> | paleocoordinates = <!--{{coord|20.9|S|93.0|E|display=inline}}--> | unitof = | subunits = | underlies = | overlies = | thickness = <!--{{convert|1|m|ft|abbr=on}}--> | extent = Li Basin | area = | map = <!--{{Location map+ | Thailand | relief = 1 | width = 250 | float = center | places = {{Location map~ | Thailand | lat_deg = 16.3 | lon_deg = 102.0 | mark = Yellow pog.svg | marksize = 12 }} }}--> | map_caption = }} The '''Mae Long Formation''' in the Li Basin (also referred to as '''Li Mae Long''') is a fossil site in Lamphun Province, Thailand. The fossils found are thought to date to the late Early Miocene, about 18 million years ago, corresponding to the European zone MN 4.<ref name=MG783>Mein and Ginsburg, 1997, p. 783</ref>

== Fossil content == Mammals found at the site include:<ref name=MG783/> ;Metatherians * ''Siamoperadectes minutus'' ;Lipotyphlans * ''Hylomys engesseri'' * ''Neotetracus butleri'' * ''Thaiagymnura equilateralis'' * Unidentified Erinaceidae, possibly ''Mioechinus'' * ''Scapanulus lampounensis'' ;Bats * Unidentified species possibly belonging to ''Taphozous'' * Unidentified species of ''Megaderma'' * ''Hipposideros felix'' * ''H. khengkao'' * ''Rhinolophus yongyuthsi'' * Unidentified species of Rhinolophoidea * ''Ia lanna'' * ''Rhizomops mengraii'' * Unidentified species of Vespertilionidae ;Treeshrews * ''Tupaia miocenica'' ;Primates * ?''Nycticebus linglom'' * ''Tarsius thailandica'' ;Rodents * ''Ratufa maelongensis'' * Unidentified species possibly belonging to ''Atlantoxerus'' * ''Democricetodon kaonou'' * ''Diatomys liensis'' * ''Neocometes orientalis'' * ''Potwarmus thailandicus'' * ''Prokanisamys benjavuni'' * ''Spanocricetodon janvieri'' ;Carnivorans * Two unidentified species ;Proboscideans * Unidentified species ;Perissodactyls * Unidentified species ;Artiodactyls * ''Conohyus sindiensis'' * ''Siamotragulus haripounchai'' * ''Stephanocemas rucha'' * Unidentified species possibly belonging to ''Homoiodorcas''

== References == {{reflist}}

=== Bibliography === * Mein, P. and Ginsburg, L. 1997. Les mammifères du gisement miocène inférieur de Li Mae Long, Thaïlande : systématique, biostratigraphie et paléoenvironnement. Geodiversitas 19(4):783–844 (in French). [https://web.archive.org/web/20120305203305/http://www.mnhn.fr/publication/geodiv/g97n4a4.html Abstract in French and English]

Category:Geologic formations of Thailand Category:Neogene System of Asia Category:Cenozoic paleontological sites of Asia Category:Paleontology in Thailand Category:Geography of Lamphun province