Cambridge Greensand

Not to be confused with Cambridge Formation.

The Cambridge Greensand is a geological unit in England whose strata are earliest Cenomanian in age.^[1] It lies above the erosive contact between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the lowest member bed of the West Melbury Marly Chalk Formation.^[2] It is a remanié deposit, containing reworked fossils of late Albian age, including those of dinosaurs and pterosaurs.

Cambridge Greensand
Stratigraphic range: Earliest Cenomanian ~100 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Member
Unit of	West Melbury Marly Chalk Formation
Underlies	Chalk Group
Overlies	Gault Formation
Thickness	0.1–1 m (0.33–3.28 ft)
Lithology
Primary	Glauconitic marl
Other	Phosphorite
Location
Coordinates	52.2°N 0.1°E / 52.2; 0.1
Approximate paleocoordinates	41.0°N 1.8°E / 41.0; 1.8
Region	England
Country	UK
Extent	North Hertfordshire and Cambridgeshire
Type section
Named for	Cambridge
Location	Arlesey Brickpit
Cambridge Greensand (England)

Description

The lithology is made out of glauconitic marl, described as a "chalk mud", containing abundant ostracod, coccolith and foram remains, with a concentration of phosphatic nodules and bones at the base.^[1][2]

Vertebrate paleofauna

Birds

Birds
Genus	Species	Locality	Material	Notes	Images
Enaliornis	E. barrette		Braincases, vertebrae, pelvis [and] limb elements[3]	This genus is the oldest known hesperornithine
	E sedgwicki		Hindlimb elements[3]
	E. seeleyi		Assorted cranial and postcranial elements

Dinosaurs

Ornithischians

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.

Ornithischians
Genus	Species	Locality	Material	Notes	Images
Anoplosaurus	A. curtonotus		"Partial postcranium"[4]
	A. major		"Cervical vertebrae."[4] "Vertebrae."[5]
Acanthopholis	A. eucercus		"[Two] caudal centra."[4]	Nomen dubium
	A. platypus		"Phalanx, caudal centra."[4]	Nomen dubium
	A. macrocercus		"Osteoderms."[4] "Vertebrae, fragmentary skeleton elements."[5]	Reassigned to Syngonosaurus
	A. stereocercus		"Osteoderms."[4] "Vertebrae."[5]	Nomen dubium
Eucercosaurus	E. tanyspondylus		"Vertebrae."[4]
Trachodon	T. cantabrigiensis		"Dentary tooth."[6]	Nomen dubium

Saurischians

Saurischians
Genus	Species	Locality	Material	Notes	Images
Macrurosaurus	M. semnus		"Caudal vertebrae"[7]	Titanosauriform sauropod or indeterminate macronarian

Pterosaurs

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.

Pterosaurs
Genus	Species	Locality	Material	Notes	Images
Aerodraco[8]	A. sedgwickii[8]		Anterior rostrum
Amblydectes	A. crassidens[9]		Jaw fragments
	A. eurygnathus[10]		Jaw fragments	Possibly a junior synonym of A. crassidens[9]
Camposipterus	C. colorhinus[10]		Anterior rostra fragments
	C. nasutus[10]		Partial rostrum
Draigwenia	D. platystomus[10]		Anterior rostrum fragments	Formerly Amblydectes platystomus[9]
Lonchodraco	L. machaerorhynchus[10]			May[11] or may not[12] be referrable to Ikrandraco
	L. microdon[10]			Junior synonym of L. machaerorhynchus[11]
Nicorhynchus	N. capito[10][13]		Jaw fragments	Possibly synonymous with Coloborhynchus[14]
Ornithocheirus	O. simus[10][15]
	"Ornithocheirus" denticulatus[10]
	"Ornithocheirus" polyodon[10]
Ornithostoma[16][17]	O. sedgwicki		Jaw fragments	Azhdarchoid pterosaur[17]
Indeterminate azhdarchoid			Jaw fragments	Likely represents a distinct taxon from Ornithostoma[18]

Ichthyosaurs

Ichthyosaurs
Genus	Species	Locality	Material	Notes	Images
Cetarthrosaurus	C. walkeri[19]
Maiaspondylus	M. cantabrigiensis
Pervushovisaurus	P. campylodon
Sisteronia	S. seeleyi

Lepidosauria

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.

Lepidosauria
Genus	Species	Locality	Material	Notes	Images
Patricosaurus	P. merocratus[20]			Chimeric specimen

Invertebrates

Ammonites

• Salaziceras salazacense^[21]

See also

• List of dinosaur-bearing rock formations

References

1. Hart, Malcolm B.; Fox, Lyndsey R. (2020). "Micropalaeontology and stratigraphical setting of the Cambridge Greensand". Geological Society, London, Special Publications. 498 (1): 147–163. Bibcode:2020GSLSP.498..147H. doi:10.1144/SP498-2018-144. ISSN 0305-8719. S2CID 210304478.
2. Cambridge Greensand at BGS
3. "Table 11.1," in Weishampel, et al. (2004). Page 215.
4. "Table 17.1," in Weishampel, et al. (2004). Page 367.
5. "Table 19.1," in Weishampel, et al. (2004). Page 417.
6. "Table 20.1," in Weishampel, et al. (2004). Page 443.
7. "Table 13.1," in Weishampel, et al. (2004). Page 270.
8. Holgado, B.; Pêgas, R.V. (2020). "A taxonomic and phylogenetic review of the anhanguerid pterosaur group Coloborhynchinae and the new clade Tropeognathinae". Acta Palaeontologica Polonica. 65. doi:10.4202/app.00751.2020.
9. Holgado, Borja (2021). "On the validity of the genus Amblydectes Hooley 1914 (Pterodactyloidea, Anhangueridae) and the presence of Tropeognathinae in the Cambridge Greensand". Anais da Academia Brasileira de Ciências. 93 (suppl 2). doi:10.1590/0001-3765202120201658. ISSN 1678-2690.
10. Rodrigues, Taissa & Kellner, Alexander Wilhelm Armin (2013). "Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England". ZooKeys (308): 1–112. Bibcode:2013ZooK..308....1R. doi:10.3897/zookeys.308.5559. PMC 3689139. PMID 23794925.
11. Averianov, A.O. (2020). "Taxonomy of the Lonchodectidae (Pterosauria, Pterodactyloidea)". Proceedings of the Zoological Institute RAS. 324 (1): 41–55. doi:10.31610/trudyzin/2020.324.1.41.
12. Pêgas, Rodrigo V. (2024-06-10). "A taxonomic note on the tapejarid pterosaurs from the Pterosaur Graveyard site (Caiuá Group, ?Early Cretaceous of Southern Brazil): evidence for the presence of two species". Historical Biology: 1–22. doi:10.1080/08912963.2024.2355664. ISSN 0891-2963.
13. Holgado, B.; Pêgas, R.V. (2020). "A taxonomic and phylogenetic review of the anhanguerid pterosaur group Coloborhynchinae and the new clade Tropeognathinae". Acta Palaeontologica Polonica. 65. doi:10.4202/app.00751.2020.
14. Smith, Roy E.; Ibrahim, Nizar; Longrich, Nicholas; Unwin, David M.; Jacobs, Megan L.; Williams, Cariad J.; Zouhri, Samir; Martill, David M. (September 2023). "The pterosaurs of the Cretaceous Kem Kem Group of Morocco". PalZ. 97 (3): 519–568. Bibcode:2023PalZ...97..519S. doi:10.1007/s12542-022-00642-6. ISSN 0031-0220.
15. Unwin D.M., 2001, "An overview of the pterosaur assemblage from the Cambridge Greensand (Cretaceous) of Eastern England", Mitteilungen aus dem Museum für Naturkunde in Berlin, Geowissenschaftliche Reihe 4: 189–221
16. Averianov A.O. (2012). "Ornithostoma sedgwicki – valid taxon of azhdarchoid pterosaurs". Proceedings of the Zoological Institute RAS. 316 (1): 40–49. doi:10.31610/trudyzin/2012.316.1.40.
17. Smith, Roy E.; Martill, David M.; Unwin, David M.; Steel, Lorna (February 2021). "Edentulous pterosaurs from the Cambridge Greensand (Cretaceous) of eastern England with a review of Ornithostoma Seeley, 1871". Proceedings of the Geologists' Association. 132 (1): 110–126. Bibcode:2021PrGA..132..110S. doi:10.1016/j.pgeola.2020.10.004.
18. Smith, Roy E.; Martill, David M.; Zouhri, Samir (2023). "Distinctive azhdarchoid pterosaur jaws from the mid-Cretaceous Cambridge Greensand of eastern England and the Kem Kem Group of Morocco". Proceedings of the Geologists' Association. 134 (3): 269–275. doi:10.1016/j.pgeola.2023.03.002.
19. Valentin Fischer; Nathalie Bardet; Myette Guiomar & Pascal Godefroit (2014). "High Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction". PLOS ONE. 9 (1): e84709. Bibcode:2014PLoSO...984709F. doi:10.1371/journal.pone.0084709. PMC 3897400. PMID 24465427.
20. P. M. Barrett and S. E. Evans. 2002. A reassessment of the Early Cretaceous reptile 'Patricosaurus merocratus' Seeley from the Cambridge Greensand, Cambridgeshire, UK. Cretaceous Research 23:231-240
21. C. W. Wright and W. J. Kennedy. 1979. Origin and evolution of the Cretaceous micromorph ammonite family Flickiidae. Palaeontology 22:685-704