Jydegaard Formation

Jydegaard Formation
Stratigraphic range: Late Berriasian-early Valanginian~
Type	Geological formation
Unit of	Nyker Group
Sub-units	Rødbjerg & Tornhøj Members
Underlies	Arnager Greensand Formation
Overlies	Robbedale Formation
Lithology
Primary	Claystone, sandstone
Location
Coordinates	55°06′N14°48′E / 55.1°N 14.8°E / 55.1; 14.8
Approximate paleocoordinates	47°12′N21°24′E / 47.2°N 21.4°E / 47.2; 21.4
Region	Bornholm
Country	Denmark
Jydegaard Formation (Denmark)

The Jydegaard Formation (also spelled as 'Jydegård') is a geological formation dating to the Early Cretaceous, about 145–139 million years ago. It is on the island of Bornholm, Denmark. Vertebrate fossils have been found in the formation.^[1]

Fossil content

Thin bone fragments have been uncovered that may belong to pterosaurs or birds.^[1]

Dinosaurs

A tooth possibly belonging to a juvenile titanosaur has been found in the formation.^[1]

Genus	Species	Location	Material	Description	Images
Dromaeosauroides[1]	D. bornholmensis[1]	Robbedale[1]	Two teeth and possible coprolites.[2]		Holotype tooth Life Reconstruction

Crocodylomorphs

Genus	Species	Location	Material	Description	Images
Pholidosaurus[1]	unknown	Robbedale[1]	A tooth tentatively referred to Pholidosaurus[3]		Possible tooth

Fish

Fish remains have been found in coprolites possibly belonging to the dromaeosaur Dromaeosauroides or marine turtles. Also, unidentified pycnodont jaws and two small stem-teleosteans have been uncovered. Amioid scales have also been revealed.^[1]

Genus	Species	Location	Material	Description	Images
Lepidotes[1]	L. sp[1]	Robbedale[1]	Teeth, jaws and scales[1]
Hybodus[2]	unknown	Robbedale[2]	Teeth and scales[2]
Parvodus[1]	P. rugianus[4]	Robbedale[1]	Teeth, finspines and head "hooks"[1]
Pleuropholis[1]	P. serrata[5]	Robbedale[1]	unknown

Turtles

Unidentified turtlecarapaces have been uncovered in the Formation.^[1]

Lizards

A lower jaw from a lizard has been recovered from the formation.^[1]

Bivalves

Genus	Species	Location	Material	Description	Images
Neomiodon[1]	unknown	Robbedale[1]	many specimens[1]	Neomiodon specimens are thought to be victim to a mass mortality such as poisoning.[1]
Viviparus[1]	unknown	Robbedale[1]	many specimens[1]	Viviparus specimens are thought to be victim to a mass mortality such as poisoning.[1]

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.

See also

• List of fossiliferous stratigraphic units in Denmark

References

1. Bonde, Niels; Christiansen, Per (2003). "New dinosaurs from Denmark". Comptes Rendus Palevol. 2 (1): 13–26. Bibcode:2003CRPal...2...13B. doi:10.1016/S1631-0683(03)00009-5.
2. Milàn, J.; Rasmussen, B. W.; Bonde, N. (2012). "Coprolites with prey remains from the Lower Cretaceous (Late Berriasian) Jydegaard Formation of Bornholm, Denmark"(PDF). New Mexico Museum of Natural History and Science. Bulletin. 57: 235–240. Archived from the original(PDF) on 2016-03-04. Retrieved 2013-09-25.
3. Schwarz-Wings, D.; Rees, J.; Lindgren, J. (2009). "Lower Cretaceous Mesoeucrocodylians from Scandinavia (Denmark and Sweden)". Cretaceous Research. 30 (5): 1345. Bibcode:2009CrRes..30.1345S. doi:10.1016/j.cretres.2009.07.011.
4. "Parvodus rugianus". Paleobiology Database. Retrieved 25 September 2013.
5. "Pleuropholis serrata". Paleobiology Database. Retrieved 25 September 2013.

Further reading

• J. Rees. 2000. An Early Cretaceous scincomorph lizard dentary from Bornholm, Denmark. Bulletin of the Geological Society of Denmark 48:105-109