The 'Yixian Formation' is a
geological formation in
Liaoning,
People's Republic of China, that stems from the
early Cretaceous period. It is known for its
fossils. It was initially recognized during the time the
Japanese Empire controlled a large chunk of
Manchuria (Northern China) called "
Jehol". During the occupation of Jehol, many Japanese scientists had noticed fossil remains of extinct fish and reptiles, possibly the
champsosaurs. These initial fossil discoveries made by Japanese scientists vanished from history once
World War II ended in
1945. By
1949, when administration of the area passed to the Communist Party and its leader
Mao Tse-Tung, the fossils of Yixian were studied only by Chinese scientists. It was not until the 1990s when remarkable fossils of birds and dinosaurs were excavated. Since
1996, a number of
dinosaur fossils that have revolutionized knowledge of these animals have been found at Yixian; among them are the first known non-
avian theropods with
feathers.
Fossil taxa
Fossils found in the Yixian Formation include:
Dinosaurs (including birds)
'
Theropods'
★ ''
Sinosauropteryx'', the first dinosaur found here (
compsognathid)
★ ''
Huaxiagnathus'' (compsognathid)
★ ''
Sinocalliopteryx'' (compsognathid)
★ ''
Beipiaosaurus'' (
therizinosaur)
★ ''
Caudipteryx'' (
oviraptorosaur)
★ ''
Incisivosaurus'' (oviraptorosaur)
★ ''
Protarchaeopteryx'' (oviraptorosaur)
★ ''
Dilong'' (
tyrannosauroid)
★ ''
Mei'', a small dinosaur that has been fossilized in a sleeping position, with its head under a wing (
deinonychosaur)
★ ''
Microraptor'' (deinonychosaur)
★ ''
Sinovenator'' (deinonychosaur)
★ ''
Sinornithosaurus'' (deinonychosaur)
★ ''
Scansoriopteryx''? (
scansoriopterygid)
★ ''
Shenzhousaurus'' (
ornithomimosaur)
★ ''
Shenzhouraptor'' AKA ''Jeholornis'' (avian:
basal bird)
★ ''"
Liaoxiornis"'' (avian? A ''
nomen dubium'')
★ ''
Sapeornis'' (avian:
omnivoropterygiform)
★ ''
Confuciusornis'' (avian: basal
pygostylian)
★ ''
Sinornis/
Cathayornis'' (
avian:
enantiornithine)
★ ''
Longipteryx'' (avian: enantiornithine?)
★ ''
Liaoningornis'' (avian:
liaoningornithiform)
'
Cerapods'
★ ''
Liaoceratops'' (
ceratopsian)
★ ''
Psittacosaurus'' (ceratopsian)
★ ''
Jeholosaurus'' (
ornithopod)
★ ''
Jinzhousaurus'' (ornithopod)
'
Thyreophorans'
★ ''
Liaoningosaurus'' (
ankylosaurian)
Pterosaurs
★ ''
Sinopterus''
★ ''
Haopterus''
★ ''
Jeholopterus''
★ ''
Eosipterus''
★ ''
Beipiaopterus''
★ ''
Boreopterus''
★ ''
Feilongus''
Mammals
'
Symmetrodonts'
★ ''
Akidolestes''
★ ''
Maotherium''
★ ''
Zhangheotherium''
'
Triconodonts'
★ ''
Jeholodens''
★ ''
Repenomamus'', which ate small dinosaurs
★ ''
Yanoconodon''
'
Multituberculates'
★ ''
Sinobaatar''
'
Metatheria' (marsupials)
★ ''
Sinodelphys''
'
Eutheria' (placental mammals)
★ ''
Eomaia''
Other vertebrates
'
Lepidosaurians'
★ ''
Dalinghosaurus'', a lizard
★ ''
Xianglong'', a gliding lizard
★ ''
Yabeinosaurus'', a lizard related to
geckos and
skinks
'
Choristoderans'
★ ''
Hyphalosaurus''
★ ''
Monjurosuchus''
'
Turtles'
★ ''
Manchurochelys''
'
Amphibians'
★ ''
Jeholotriton'', a gilled salamander
★ ''
Callobatrachus'', a frog
★ ''
Mesophryne'', a frog with no known living relatives
'
Fish'
★ ''
Peipiaosteus'', a fish related to
sturgeons
★ ''
Lycoptera'', herring-like fish
★ ''
Sinamia''
★ ''
Mesomyzon mengae'', a fossil
lamprey
Insects and other arthropods
★ giant
water strider bug
★ Jehol
crayfish
★ Orb-weaving
spider
★
Mayfly
★ Carrion-eating
beetles
★
Cicada
★
Dragonfly
★
Cockroach
★ ''
Palaepangonius'', an early pollinating fly

Fossil of ''
Archaefructus'', an extinct genus aquatic plants, found at the Yixian Formation.
Plants
★ ''
Archaefructus''
★
Horsetail
★ ''
Ephedra''
★
Conifer trees
★
Ginkgo trees
★ ''
Archaeamphora'', the earliest known carnivorous plant
See also
★
List of fossil sites ''(with link directory)''
References