McCoy Brook Formation explained

McCoy Brook Formation
Type:	Geological formation
Period:	Sinemurian
Namedfor:	McCoy Brook, Nova Scotia
Coordinates:	45.4°N -64.2°W
Paleocoordinates:	27.4°N -13.3°W
Unitof:	Newark Supergroup  Meriden Group
Subunits:	Scots Bay Member
Underlies:	Erosional top
Overlies:	North Mountain Basalt
Thickness:	more than 230m (760feet)
Extent:	Bay of Fundy

The McCoy Brook Formation is a geological formation dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages. The McCoy Brook Formation is found in outcrops around the Bay of Fundy, Nova Scotia.^[1]

Agen

The McCoy Brook Formation rests on the North Mountain Basalt, one of the volcanic flows associated with the Triassic–Jurassic boundary in the Newark Supergroup. The base of the McCoy Brook Formation is probably within 100,000 to 200,000 years of the boundary.^[2]

Scots Bay Member

This thin unit (9 m) of lacustrine sediments is preserved in six small synclinal outcrops around Scots Bay on the west side of the Blomidon Peninsula. Originally named as the Scots Bay Formation, it is now correlated with the lowermost part of the McCoy Brook Formation, where it is referred to as the Scots Bay Member.^{[3] [4]} The Scots Bay Member accumulated in an aerobic lake on the floor of the subtropical Fundy Rift Valley, associated with Silica-rich Hydrothermal Springs derived from the CAMP vulcanism, where the biota is composed of algal Stromatolites, Oncolites, Charophyta, Ostracoda, Gastropoda, Conchostraca, fish bones, calcispheres and logs.^[5]

Fossil content

Ray-finned fish

Ray-finned fish
Name	Species	Location	Stratigraphic position	Material	Notes	Images
?Redfieldiid^[7]	None designated	Wasson Bluff	Scots Bay member	Scales and skull bones	Found in lacustrine limestone and lacustrine basalt aggregate
aff. Semionotus sp.	None designated	Wasson Bluff	Scots Bay member	Disarticulated remains	Found in lacustrine limestone, lacustrine basalt aggregate, and lacustrine mudstone

Synapsids

Synapsids
Name	Species	Location	Stratigraphic position	Material	Notes	Images
Cynodontia	Indeterminate	Wasson Bluff	Scots Bay Member	Partial right unla Proximal portion of a right ischium	A cynodont
Oligokyphus^[8]	Oligokyphus sp.	Wasson Bluff	Scots Bay Member	Fragment of a right Dentary.	A tritheledontid cynodont, found in the layers of the Scots Bay member.
Pachygenelus^[9]	cf. P. monus	Wasson Bluff	Upper Member	Excellently preserved fragments of two premaxillae, ten maxillae, and six dentaries	A tritheledontid cynodont
Tritylodontidae	Indeterminate	Wasson Bluff	Scots Bay Member	Right humerus	A tritylodontid cynodont, found in the layers of the Scots Bay member.

Sphenodonts

Sphenodonts
Name	Species	Location	Stratigraphic position	Material	Notes	Images
Clevosaurus^[10]	C. bairdi	Wasson Bluff	Lower McCoy Brook Formation	Partial skulls and jaws, isolated cranial bones, partial postcranium, postcranial bones	A sphenodontian of relatively small size, found in fluvio-lacustrine sandstone and mudstone, and basalt agglomerate
cf. Palycymalia	Indeterminate	Wasson Bluff	Middle McCoy Brook Formation	Isolated Remains	A sphenodontian
cf. Sigmala	Indeterminate	Wasson Bluff	Middle McCoy Brook Formation	Isolated Remains	A sphenodontian

Crocodyliforms

Protosuchidae
Genus	Species	Location	Stratigraphic position	Material	width=25%	Notes	Images
Protosuchus^[11]	P. micmac	Wasson Bluff	Lower McCoy Brook Formation	Partial lower jaw, several other skull bones	Found in fluvio-lacustrine sandstone and mudstone, and basalt agglomerate
Sphenosuchid	Indeterminate	Blue sack west Wasson Bluff	Lower McCoy Brook Formation	A maxilla Isolated Osteoderms	Found in fluvio-lacustrine sandstone and mudstone, and basalt agglomerate

Dinosaurs

Sauropodomorpha

Ichnotaxa

Ichnotaxa
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Anchisauripus	A. sillimani A. ispp.	Blue sack west McKay Head Wasson Bluff	Middle McCoy Brook Formation	Footprints	Small Theropod Footprints
Anomoepus	A. scambus A. ispp.	Blue sack west McKay Head Old Wife Point tracksite	Middle McCoy Brook Formation	Footprints	Ornithischian Footprints
Batrachopus^[13]	B. deweyii B. dispar B. ispp.	McKay Head Old Wife Point tracksite Wasson Bluff tracksite	Middle McCoy Brook Formation	Footprints	Crocodrylomorph Footprints
Eubrontes	E. giganteus E. sillimani E. minusculus E ispp.	Five Islands Provincial Park Old Wife Point tracksite Wasson Bluff tracksite	Middle McCoy Brook Formation	Footprints	Medium-sized Theropod Footprints
Grallator	G. cursorius G. tenuis G. ispp.	McKay Head Old Wife Point tracksite	Middle McCoy Brook Formation	Footprints	Small Theropod Footprints
Otozoum^[14]	O. moodi O. ispp.	Blue sack east McKay Head Minas Basin tracksite	Middle McCoy Brook Formation	Footprints	Sauropodomorph Footprints

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with few dinosaur genera

Notes and References

1. Van Drecht . L. . Sedimentology and Paleoenvironment of an Early Jurassic Dinosaur Bone Bed, Wasson Bluff, Parrsboro, Nova Scotia . Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Sciences, Honours Department of Earth Sciences Dalhousie University, Halifax . 2014 . 1–80 . 11 October 2023.
2. Book: Shubin, N. H. . Olsen, P. E. . Sues, H.-D. . 1994 . Early Jurassic small tetrapods from the McCoy Brook Formation of Nova Scotia, Canada . 242–250 . Fraser, N. C. . Sues H. D. . In the Shadow of the Dinosaurs . Cambridge University Press . Cambridge, United Kingdom . 0-521-45899-4 .
3. Tanner. L.H.. 1996. Formal definition of the Lower Jurassic McCoy Brook Formation, Fundy Rift Basin, eastern Canada. Atlantic Geology. 32. 2 . 127–135. 10.4138/2083 . 15 December 2012.
4. Web site: Sedimentology and Paleontology of the Lower Jurassic Scots Bay Formation, Bay of Fundy, Nova Scotia, Canada. Hassan. H.S.. MSc thesis. 24 November 2012.
5. De WET . C. C. B. . Hubert . J. F. . The Scots Bay formation, Nova Scotia, Canada, a Jurassic carbonate lake with Silica-rich hydrothermal springs . Sedimentology . 1989 . 36 . 5 . 857–873 . 10.1111/j.1365-3091.1989.tb01750.x . 1989Sedim..36..857W . 11 October 2023.
6. Sues . H. D. . Olsen . P. E. . Stratigraphic and temporal context and faunal diversity of Permian-Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada . Atlantic Geology . 2015 . 51 . 1 . 139–205 . 10.4138/atlgeol.2015.006 . 11 October 2023.
7. Olsen . P. E. . Paleontology and paleoecology of the Newark Supergroup (early Mesozoic, eastern North America) . Developments in Geotectonics . 1988 . 22 . 1 . 185–230 . 10.1016/B978-0-444-42903-2.50013-0 . 978-0-444-42903-2 . 11 October 2023.
8. Fedak . Tim . Sues . Hans-Dieter . Olsen . Paul E. . First record of the tritylodontid cynodont Oligokyphus and cynodont postcranial bones from the McCoy Brook Formation of Nova Scotia, Canada . Canadian Journal of Earth Sciences . 2015 . 52 . 4 . 244–249 . 10.1139/cjes-2014-0220 . 2015CaJES..52..244F . 11 October 2023.
9. Shubin . N. H. . Crompton . A. W. . Sues . H.D. . Olsen . P. E. . New fossil evidence on the sister-group of mammals and early Mesozoic faunal distributions . Science . 1991 . 251 . 4997 . 1063–1065 . 10.1126/science.251.4997.1063 . 17802092 . 1991Sci...251.1063S . 11 October 2023.
10. Sues . H.-D. . Shubin, N. H. . Olsen, P. E. . 1994 . A new sphenodontian (Lepidosauria: Rhynchocephalia) from the McCoy Brook Formation (Lower Jurassic) of Nova Scotia, Canada . Journal of Vertebrate Paleontology . 14 . 3 . 327–340 . 10.1080/02724634.1994.10011563. 1994JVPal..14..327S .
11. Sues . H.-D. . Shubin, N. H. . Olsen, P. E. . Amaral, W. W. . 1996 . On the cranial structure of a new protosuchid (Archosauria: Crocodyliformes) from the McCoy Brook Formation (Lower Jurassic) of Nova Scotia, Canada . Journal of Vertebrate Paleontology . 16 . 1 . 34–41 . 10.1080/02724634.1996.10011281 . 1996JVPal..16...34S .
12. Fedak . Timothy J. . Description and evolutionary significance of the sauropodomorph dinosaurs from the early Jurassic (Hettangian) McCoy Brook Formation . Thesis (Ph.D.)--Dalhousie University (Canada) . 2007 . 1–271 . 11 October 2023.
13. Olsen . P. E. . Stop 11.3: Wasson Bluff. Paleontology . Tectonic, Depositional, and Paleoecological History of Early Mesozoic Rift Basins, Eastern North America . 1989. 351 . 2 . 159–161.
14. Grantham . R. G. . Dinosaur tracks and mega-flutes in the Jurassic of Nova Scotia . First International Symposium on Dinosaur Tracks and Traces . 1986 . 14.