McCoy Brook Formation

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]

McCoy Brook Formation
Stratigraphic range: Hettangian–Sinemurian PreꞒ Ꞓ O S D C P T J K Pg N
Breccia in the McCoy Brook Formation (Jurassic), Wasson's Bluff, Nova Scotia.
Type	Geological formation
Unit of	Newark Supergroup  Meriden Group
Sub-units	Scots Bay Member
Underlies	Erosional top
Overlies	North Mountain Basalt
Thickness	more than 230 m (750 ft)
Location
Coordinates	45.4°N 64.2°W / 45.4; -64.2
Approximate paleocoordinates	27.4°N 13.3°W / 27.4; -13.3
Region	Nova Scotia
Country	Canada
Extent	Bay of Fundy
Type section
Named for	McCoy Brook, Nova Scotia
McCoy Brook Formation (Canada) Show map of Canada McCoy Brook Formation (Nova Scotia) Show map of Nova Scotia

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

Sharks

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.

Sharks
Name	Species	Location	Stratigraphic position	Material	Notes
cf.Hybodus[2][6]	Indeterminate	Wasson Bluff	Scots Bay member	Teeth & Coprolites	A hybodont shark. Recovered from lacustrine facies	Two Hybodus

Ray-finned fish

Ray-finned fish
Name	Species	Location	Stratigraphic position	Material	Notes	Images
?Redfieldiid[2][7]	None designated	Wasson Bluff	Scots Bay member	Scales and skull bones[2]	Found in lacustrine limestone and lacustrine basalt aggregate
aff. Semionotus sp.[2][7]	None designated	Wasson Bluff	Scots Bay member	Disarticulated remains	Found in lacustrine limestone, lacustrine basalt aggregate, and lacustrine mudstone	Semionotus

Synapsids

Synapsids
Name	Species	Location	Stratigraphic position	Material	Notes	Images
Cynodontia[7][8]	Indeterminate	Wasson Bluff	Scots Bay Member	Partial right unla Proximal portion of a right ischium	A cynodont
Oligokyphus[7][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.	Oligokyphus
Pachygenelus[7][9]	cf. P. monus	Wasson Bluff	Upper Member	Excellently preserved fragments of two premaxillae, ten maxillae, and six dentaries	A tritheledontid cynodont	Pachygenelus
Tritylodontidae[7][8]	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[10]	Wasson Bluff	Lower McCoy Brook Formation	Partial skulls and jaws, isolated cranial bones, partial postcranium, postcranial bones	A sphenodontian of relatively small size,[10] found in fluvio-lacustrine sandstone and mudstone, and basalt agglomerate	Clevosaurus
cf. Palycymalia[6][7]	Indeterminate	Wasson Bluff	Middle McCoy Brook Formation	Isolated Remains	A sphenodontian
cf. Sigmala[6][7]	Indeterminate	Wasson Bluff	Middle McCoy Brook Formation	Isolated Remains	A sphenodontian

Crocodyliforms

Protosuchidae
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Protosuchus[6][11]	P. micmac[11]	Wasson Bluff	Lower McCoy Brook Formation	Partial lower jaw, several other skull bones[11]	Found in fluvio-lacustrine sandstone and mudstone, and basalt agglomerate[2]	Protosuchus
Sphenosuchid[2][6]	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

Ornithischia

Ornithischians
Genus	Species	Location	Stratigraphic position	Material	Notes
Ornithischia[2][7][6]	Indeterminate	Wasson Bluff	Scots Bay Member	Impressions of teeth (YPM VP 008668, VP 008691) Vertebral centra (YPM VP 008693) Possible rib fragments (YPM VP008694, VP 008695)	Suggested to be similar to Scutellosaurus and to Leshotosaurus. Represent among the oldest reliable Ornithischian remains of North America.

Theropoda

Ornithischians
Genus	Species	Location	Stratigraphic position	Material	Notes
Theropoda[1][6]	Indeterminate	Wasson Bluff	Scots Bay Member	Teeth	Theropod dinosaur teeth similar to Megapnosaurus.

Sauropodomorpha

Sauropodomorph dinosaurs
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Fendusaurus[12]	F. eldoni	Wasson Bluff	Middle McCoy Brook Formation	YPM VPPU 022196, several vertebrae and limb-bone fragments FGM994GF69, postcranial skeleton FGM998GF9, partial skeleton FGM998GF13_I, large, articulated specimen FGM998GF13/FGM998GF13_III postcranea and dissociated skull NSM005GF009/FGM998GF46, partial, badly deformed and fragmentary skeleton with gastroliths	Although long assigned to Ammosaurus, the material actually represents a new genus and species; represents the most abundant dinosaur in the formation, and has yield specimens with preserved stomach contents that suggest migration patterns. The possibility that represents more than one genus is open.[6]

Ichnotaxa

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.

Ichnotaxa
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Anchisauripus[6]	A. sillimani A. ispp.	Blue sack west McKay Head Wasson Bluff	Middle McCoy Brook Formation	Footprints	Small Theropod Footprints
Anomoepus[2][6]	A. scambus A. ispp.	Blue sack west McKay Head Old Wife Point tracksite	Middle McCoy Brook Formation	Footprints	Ornithischian Footprints
Batrachopus[6][13]	B. deweyii B. dispar B. ispp.	McKay Head Old Wife Point tracksite Wasson Bluff tracksite	Middle McCoy Brook Formation	Footprints	Crocodrylomorph Footprints
Eubrontes[6][13]	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[2][6]	G. cursorius G. tenuis G. ispp.	McKay Head Old Wife Point tracksite	Middle McCoy Brook Formation	Footprints	Small Theropod Footprints	Grallator
Otozoum[6][2][14]	O. moodi O. ispp.	Blue sack east McKay Head Minas Basin tracksite	Middle McCoy Brook Formation	Footprints	Sauropodomorph Footprints	Otozoum

See also

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