Coordinates: 30°48′N 111°18′E / 30.8°N 111.3°E / 30.8; 111.3

Yanjiahe Formation

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Yanjiahe Formation
Stratigraphic range: Ediacaran - Fortunian
~542–529 Ma [1]
TypeFormation
Sub-unitsSee: Beds
OverliesDengying Formation
Lithology
PrimaryShale, limestone, dolomite
OtherChert, phosphorite
Location
CoordinatesLua error in Module:Coordinates at line 489: attempt to index field 'wikibase' (a nil value).
Approximate paleocoordinatesLua error: callParserFunction: function "#coordinates" was not found.
RegionHubei
CountryChina
ExtentYangtze Gorges
Yanjiahe Formation (China)
Yanjiahe Formation (Hubei)

The Yanjiahe Formation is an Ediacaran to Cambrian fossiliferous geologic formation found in South China.[2][3]

Dating

[edit | edit source]

The Yanjiahe Formation has been dated through various methods. The top of the formation is dated at 526.5±1.1 Ma and 526.4±5.3 Ma using radiometric dating on ash beds within the area. Likewise, the base of the formation has been dated to between 542±0 Ma to 526±0 Ma through carbon isotopic correlations.[1]

Beds

[edit | edit source]

The Yanjiahe Formation consists of five beds. Every bed within the formation contains fossil material.[4]

The beds are as follows, listed by ascending age:

  • Bed 1 is characterized by basal dolomitic conglomerates, with banded black cherts.[4]
  • Bed 2 is mostly consists of siliceous phosphatic dolostone, with flat pebble conglomerates.[4]
  • Bed 3 is characterized by various shales, with the presence of siliceous-phosphatic nodules.[4]
  • Bed 4 is composed of carbonaceous limestones.[4]
  • Bed 5 is characterized by cherts and siliceous phosphatic dolostone, with flat pebble conglomerates.[4]

Paleobiota

[edit | edit source]

The Yanjiahe Formation contains a wide range of unique organisms from the base of the Cambrian, from Yanjiahella to Beretella, alongside a lot of early molluscs, like Watsonella.[3]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Cnidaria

[edit | edit source]
Genus Species Notes Images
Octapyrgites[5]
  • O. elongatus
 Olivooid Medusozoan, larger than any known Olivooid.
Quadrapyrgites[6][7]
  • O. quadratacris
 Olivooid Medusozoan.
Olivooides[6][7]
  • Olivooides sp.
  • O. multisulcatus
  • O. mirabilis
 Olivooid Medusozoan.
Pseudooides[6][7]
  • Pseudooides sp.
 Medusozoan.
Septuconularia[8][9]
  • S. yanjiaheensis
  • S. crassiformis
 Hexangulaconulariid Medusozoan.
Decimoconularia[10]
  • D. isofacialis
 Hexangulaconulariid Medusozoan.
Carinachites[6][7]
  • C. spinatus
 Cnidarian sclerite, related to the conulariids.
Cambrorhytium[11]
  • C. major
 Elongated cone-like cnidarian.

Chancelloriida

[edit | edit source]
Genus Species Notes Images
Chancelloria[7]
  • Chancelloria sp.
 Sponge-like eumetazoan.
File:Chancelloria eros fossil, Middle Cambrian, Millard County UT.jpg

Deuterostome

[edit | edit source]
Genus Species Notes Images
Protohertzina[12][7]
  • P. unguliformis
  • P. anabarica
  • P. robusta
 Possibly a Protoconodont, Paraconodont, or a Chaetognath.
Tarimspira[6]
  • T. plana
 Possible Paraconodont.
Yunnanodus[12][1]
  • Yunnanodus sp.
  • Y. yanjiahensis
 Possible Paraconodont.
Yanjiahella[13]
  • Y. biscarpa
 Possibly earliest stem group echinoderm.
File:Yanjiahella biscarpa.png
Yuknessia[14]
  • Yuknessia sp.
 Unbranched pterobranch.
Error creating thumbnail:
Hertzina[12]
  • H. guizhouensis
  • H. tenuis
 Furnishinid Paraconodont.

Ecdysozoa

[edit | edit source]
Genus Species Notes Images
Beretella[15]
  • B. spinosa
 Possibly adult or larval ecdysozoan.
File:Artistic three-dimensional reconstructions of Beretella spinosa.jpg
Saccorhytus[6][7]
  • Saccorhytus sp.
 Possibly adult or larval ecdysozoan.
File:Saccorhytus.png

Lophotrochozoa

[edit | edit source]
Genus Species Notes Images
Conotheca[14][12]
  • C. subcurvata
  • C. obesa
  • C. nana
  • C. transulcata
 Hyolith lophotrochozoan.
Hyolithellus[12]
  • H. tenuis?
  • H. decorus
 Annelid lophotrochozoan, previously thought to be a Hyolith.
Lapworthella[14]
  • Lapworthella sp.
 Tommotid lophotrochozoan.
Spinulitheca[12]
  • S. billingsi
 Hyolith lophotrochozoan.
Microcornus[12]
  • M. parvulus?
 Hyolith lophotrochozoan.
Cupitheca[12]
  • C. mira
 Hyolith lophotrochozoan.
File:Figure S3-166.tif
Turcutheca[12]
  • T. crasseocochlia
  • T. lubrica
 Hyolith lophotrochozoan.
Lophotheca[12]
  • L. costellata
 Hyolith lophotrochozoan.
Circotheca[12][1]
  • C. longiconica
  • C. longiconica
 Circothecid Hyolith.
Aldanella[14][12]
  • A. attleborensis
  • A. yanjiaheensis
 Mollusc with a coiled shell.
Eohalobia[16][6][1]
  • E. diadongensis
  • Eohalobia sp.
 Halkieriid mollusc.
Ocruranus[6][16][7][1]
  • Ocruranus sp.
  • O. trulliformis
  • O. finial
 Halkieriid mollusc.
Scenella[12]
  • S. jijiapoensis
 Scenellid mollusc.
File:Estonian Museum of Natural History - Scenella.png
Siphogonuchites[12]
  • S. triangularis
 Siphogonuchitid mollusc.
Xianfengella[12]
  • X. ovata
  • X. prima
 Mollusc.
Tuberoconus[6][1]
  • T. paucipapillae
 Mollusc.
Watsonella[17]
  • W. crosbyi
 Mollusc.
Anabarella[17]
  • A. plana
 Helcionelloid mollusc.
Igorella[12][17]
  • I. emeiensis
  • I. maidipingensis
  • Igorella sp.
 Helcionelloid mollusc.
Oelandiella[12][1]
  • O. korobkovi
 Helcionelloid mollusc.
Ceratoconus[6][1]
  • C. bucers
 Helcionelloid mollusc.

Porifera

[edit | edit source]
Genus Species Notes Images
Blastulospongia[18]
  • Blastulospongia sp.
 Globular demosponge, previously postured to be a radiolarian.
Hexactinellid spicules[4]
  • ???
 A collection of monaxons, diaxons and triaxons.

incertae sedis

[edit | edit source]
Genus Species Notes Images
Anabarites[2][12][7]
  • A. trisulcatus
  • A. tianzhushanensis
  • A. gracilis
  • A. ternarius
 Anabaritid small shelly fossil.
Tiksitheca[12]
  • T. korobovi
 Anabaritid small shelly fossil.
Cambrotubulus[6][7]
  • C. decurvatus
 Anabaritid small shelly fossil.
Protoconites[14]
  • P. minor
 Curved conical organism, possible relations to Cnidaria.
Purella[14][12]
  • P. antiqua
  • P. lepidites
 Small shelly fossil.
Emeiconus[14]
  • E. antiqua
 Small shelly fossil.
Rugatotheca[7]
  • Rugatotheca sp.
 Small shelly fossil.
Coleolella[6]
  • C. recta
 Small shelly fossil.
Vendotaenid[14]
  • Vendotaenia sp.
 Ribbon-like organism.
File:Vendotaenid indet.jpg
Torellella[1]
  • T. lentiformis
 Tubicolous fossil.

Flora

[edit | edit source]
Genus Species Notes Images
Archaeophycus[2][19][7]
  • A. yunnanensis
 Either a cyanobacteria or the early developmental stage of an alga.
File:Fossils from the Weng'an biota.jpg
(J)
Konglingiphyton[14]
  • Konglingiphyton sp.
 Macroalgae.
Megathrix[2][20][19]
  • M. longus
 Filamentous cyanobacterium.
Myxococcoides[19]
  • Myxococcoides spp.
 Cyanobacteria.
Archaeooides[7]
  • A. granulates
 Microalgae.

Microorganisms

[edit | edit source]
Genus Species Notes Images
Asteridium[20]
  • A. tornatum
 Acritarch.
Comasphaeridium[2][20]
  • C. annulare
 Acritarch.
Heliosphaeridium[2][20]
  • H. ampliatum
 Acritarch.
Micrhystridium[14]
  • M. regulare
 Acritarch.
Yurtusia[19]
  • Y. uniformis
 Acritarch.
Dictyotidium[19]
  • Dictyotidium sp.?
 Acritarch.

Undescribed

[edit | edit source]
Genus Species Notes Images
Unnamed probable cnidarian[11]
  • ???
 Curved tubular organism, possible affinities to cnidarians.


See also

[edit | edit source]


References

[edit | edit source]
  1. ^ a b c d e f g h i j Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  2. ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  3. ^ a b Yanjiahe Formation at Fossilworks.org
  4. ^ a b c d e f g Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  5. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  6. ^ a b c d e f g h i j k l Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  7. ^ a b c d e f g h i j k l m Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  8. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  9. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  10. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  11. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  12. ^ a b c d e f g h i j k l m n o p q r s t Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  13. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  14. ^ a b c d e f g h i j Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  15. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  16. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  17. ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  18. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  19. ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  20. ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

Further reading

[edit | edit source]
  • P. Chen. 1984. Discovery of Lower Cambrian small shelly fossils from Jijiapo, Yichang, west Hubei and its significance. Professional Papers of Stratigraphy and Palaeontology 13:49-64
Retrieved from "http://70.231.62.181/index.php?title=Yanjiahe_Formation&oldid=20652407"