Nanxiong Formation
Geological formation in China
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The Nanxiong Formation (also known as Yuanpu Formation) is a Late Cretaceous geologic formation in Jiangxi and Guangdong Provinces. Dinosaur remains are among the fossils that have been recovered from the formation.
Several kilometers (Nanxiong Group)
| Nanxiong Formation | |
|---|---|
| Stratigraphic range: Maastrichtian | |
| Type | Geological formation |
| Underlies | Shanghu Formation |
| Overlies | Jurassic granite basement, Changba Formation (Nanxiong Group) |
| Thickness | ~300 m (980 ft) Several kilometers (Nanxiong Group) |
| Lithology | |
| Primary | Sandstone, siltstone, mudstone |
| Other | Limestone, conglomerate |
| Location | |
| Coordinates | 23.5°N 114.9°E |
| Approximate paleocoordinates | 23.8°N 110.5°E |
| Region | Jiangxi Province, Guangdong Province |
| Country | China |
| Extent | Nanxiong Basin |
  Nanxiong Formation (China)  Nanxiong Formation (Guangdong) | |
Description
It consists of continental siliciclastic red beds, with fauna which similar to that of the Nemegt Formation. It has been dated to about 66.7 ± 0.3 million years ago.[1] It is the lowest unit of the Nanxiong Basin, a small graben created during Mesozoic rifting.[2] Buck et al. state that it overlies Jurassic granite basement, and is conformably overlain by the Shanghu Formation.[1] Alternative stratigraphic schemes for the Nanxiong basin have been proposed,[3] one of which refers to the Nanxiong succession as the Nanxiong Group, and dividing it into the Yuanpu, Zhutian and Zhenshui formations, and overlying the Albian to Turonian Changba Formation.[4] The age of the Nanxiong basin as a whole has been constrained to 72 to 62.8 mya.[5] The KT boundary is thought to be in the pingling region, at the point of contact between the Zhenshui & Shanghu Formation. [6][7]
The Depositional environment is made up of alluvial fan facies consisting of sheetflood deposits and ephemeral braided rivers. Adjacent to these are ephemeral saline playa facies recording features such as; root traces, desiccation cracks, and calcareous paleosols. In situ desert varnish and minor paleosol development on alluvial facies due to inactivity are indicative of arid conditions. Stable carbon and oxygen isotopes from Dinosaur eggshells were used to estimate a mean annual temperature between 22–27.6 °C (71.6–81.7 °F), with positive isotope perturbations around the K/Pg boundary indicating periods where temperatures may have exceeded 27 °C (81 °F).[8][9][1]
Paleobiota of the Nanxiong Formation
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Crocodilians
| Crocodilians | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Jiangxisuchus[10] | J. nankangensis | Nearly complete skull and mandible | A crocodyloid |  | ||
Lizards
| Lizards | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Chianghsia[11] | C. nankangensis | A partial skull and lower jaws | A monstersaurian lizard | |||
| Tianyusaurus[12] | T. zhengi | A skull, mandible, first eight cervical vertebrae and nearly complete pectoral girdles | A polyglyphanodontian lizard, also known from the Qiupa Formation |  | ||
Turtles
| Turtles | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Jiangxichelys[13] | J. ganzhouensis | A complete shell | A nanhsiungchelyid turtle | |||
| Nanhsiungchelys[14] | N. wuchingensis | A partial skeleton | A nanhsiungchelyid turtle[15] | |||
| Oolithes[16][15] | O. elongatus, O. nanhsiungensis, O. rugustus and O. spheroides. | Egg and egg clutches. Some of these were probably laid by Nanhsiungchelys.[16][15] | Turtle and/or theropod eggs | .jpg) | ||
Dinosaurs
Ornithischians
| Ornithischians of the Nanxiong Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Microhadrosaurus[16] | M. nanshiungensis | Partial lower jaw from a juvenile that was about 2.6 m long | A nomen dubium hadrosaur taxon.[4] | |||
| Hadrosauropodus isp.[4] | Indeterminate | Three-toed footprints[4] | A hadrosaur | |||
| Nodosauridae indet.[17] | Indeterminate | Osteoderms | A possible nodosaurid ankylosaur | |||
Sauropods
| Sauropods of the Nanxiong Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Gannansaurus[18] | G. sinensis | A single, nearly complete dorsal vertebra and a mid-caudal vertebra | A sauropod closely related to Euhelopus |
 | ||
| Jiangxititan[19] | J. ganzhouensis | The three posteriormost cervical vertebrae with two cervical ribs, articulated with the first four dorsal vertebrae with three dorsal ribs | A somphospondylan of controversial affinities; originally described as a derived lognkosaurian titanosaur, later analyses recovered a more basal, non-titanosaurian position more likely.[20] |  | ||
Theropods
Oviraptorosaurs
| Oviraptorosaurs of the Nanxiong Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Banji[21] | B. long | Nearly complete skull and lower jaw | An oviraptorid |  | ||
| Corythoraptor[22] | C. jacobsi | Nearly complete skeleton including the skull and lower jaw | An oviraptorid with a distinct cassowary-like crest |  | ||
| Elongatoolithidae indet. | Indeterminate | Three eggs with embryonic remains.[23] | Oviraptorid eggs | .png) | ||
| Ganzhousaurus[24] | G. nankangensis | Lower jaw, leg bone, hip bone and caudal vertebrae | A transitional oviraptorid with both basal and derived traits |  | ||
| Huanansaurus[25] | H. ganzhouensis | Nearly complete skull, lower jaws, neck vertebrae, a humerus, arm fragments, lower part of the right thighbone, the upper part of the right shinbone, and parts of the right foot | An oviraptorid |  | ||
| Jiangxisaurus[26] | J. ganzhouensis | Incomplete skull, lower jaw, vertebrae, nearly complete pectoral girdle, the left forelimb, ribs, and a partially preserved pelvic girdle | An oviraptorid |  | ||
| Macroolithus | Indeterminate | Five egg clutches containing over 60 eggs.[27] | Oviraptorid eggs |  | ||
| Indeterminate | Three eggs with embryonic remains.[28] | Oviraptorid eggs | .png) | |||
| M. yaotunensis | Two eggs with embryonic remains.[29] | Oviraptorid eggs. Skeletal proportions resemble Heyuannia huangi | ||||
| M. yaotunensis | A nest of 24 eggs associated with an adult oviraptorid.[30] | Oviraptorid eggs | ||||
| Nankangia[31] | N. jiangxiensis | A partial lower jaw, vertebrae, both scapulocoracoids, a nearly complete right humerus, pubic bones, and some dorsal ribs | An oviraptorid |  | ||
|
Oviraptoridae indet. |
Indeterminate | A female individual preserving the pelvic girdle, some caudals and two eggs inside the abdominal cavity.[32] | A pregnant oviraptorid | |||
| Indeterminate | A nesting adult over a nest of eggs, preserving cervical vertebrae, arms and the pelvic region.[30] | An oviraptorid that represents the fifth nesting taxon | ||||
| Indeterminate | A female individual preserving a partial pelvic girdle, hindlimbs and some caudals with two eggs associated near the pelvic region.[33] | A pregnant oviraptorid | ||||
| Shixinggia[34] | S. oblita | Sparse postcranial remains lacking the skull | An oviraptorid | |||
| Tongtianlong[35] | T. limosus | Almost complete skeleton, portions of the arms, right leg, and tail were destroyed by TNT blasts | An oviraptorid, the pose indicates that it may have died trying to free itself from mud |  | ||
Therizinosaurs
| Therizinosaurs of the Nanxiong Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Nanshiungosaurus | N. brevispinus | Eleven cervical vertebrae, ten dorsal vertebrae, six sacral vertebrae and the pelvis.[16][36] | A therizinosaurid |  | ||
Tyrannosaurs
| Tyrannosaurs of the Nanxiong Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Material | Notes | Images | ||
| Asiatyrannus[37] | A. xui | A skull, partial legs, and fragmentary caudal vertebrae | A small-bodied tyrannosaurine |  | ||
| Qianzhousaurus[38] | Q. sinensis | A skull, lower jaw, vertebrae, both scapulocoracoids, a left femur and a left tibia | A tyrannosaurid, could represent a third species of Alioramus[39] |  | ||
|
Tyrannosauridae indet. |
Indeterminate | Two isolated teeth.[16] | A tyrannosaurid | |||
| Indeterminate | Large and well-preserved tooth.[40] | A tyrannosaurid | ||||
Other Theropods
| Genus | Species | Material | Notes | Images |
|---|---|---|---|---|
|
Theropoda indet. |
Indeterminate | A maxillary tooth that differs from tyrannosaurid and carcharodontosaurid dentition.[40] | A notably large theropod | |
| Indeterminate | Isolated dorsal vertebra.[16] | A theropod | ||