Alcobaça Formation

The Alcobaça Formation, previously known as the Guimarota Formation and also known as the Consolação Unit,^[1] is a geological formation in Portugal.^[2] It dates back to the Kimmeridgian stage of the Late Jurassic. It is an important source of information on the diversity of Late Jurassic mammals.^[3][4] Many of the fossils were collected from the now disused and flooded Camadas de Guimarota coal mine.

Alcobaça Formation
Stratigraphic range: Kimmeridgian ~156.9–152.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Sub-units	Camadas de Guimarota
Underlies	Lourinhã Formation
Overlies	Montejunto Formation
Lithology
Primary	Marl
Other	Mudstone, coal, siltstone, limestone, sandstone
Location
Coordinates	39.6°N 9.0°W / 39.6; -9.0
Approximate paleocoordinates	33.7°N 1.6°E / 33.7; 1.6
Region	Estremadura, Leiria, Lisboa
Country	Portugal
Extent	Lusitanian Basin
Type section
Named for	Alcobaça, Portugal
Named by	Choffat
Year defined	1885
Alcobaça Formation (Portugal)

Vertebrate paleofauna

Dinosaur eggs are geographically located in Lisbon District, Portugal.^[5] Dinosaur tracks are geographically located in Leiria District, Portugal.^[6]

Chondrichthyes

Chondrichthyes of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Hybodus[7]	Indeterminate	Guimarota		Isolated Teeth
Asteracanthus[7]	A. biformatus	Guimarota		isolated teeth, fin-spine and a head-spine
Polyacrodus[7]	Indeterminate	Guimarota		Isolated teeth and a fin-spine
Orectolobiformes[7]	Indeterminate	Guimarota		One isolated tooth
Batomorphi[7]	Indeterminate	Guimarota		Isolated teeth

Osteichthyes

Osteichthyes of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Macromesodon[7]	Indeterminate	Guimarota		Isolated teeth
Proscinetes[7]	Indeterminate	Guimarota		Isolated teeth and prearticulars
"Lepidotes"[7]	Indeterminate	Guimarota		isolated lateral teeth, lower jaws, ganoid scales and isolated skull bones	Two species of different size can be distinguished from the fossil material[7]
Ionoscopidae[7]	Indeterminate	Guimarota		Isolated teeth
Macrosemiidae[7]	Indeterminate	Guimarota		Isolated grasping tooth
Caturus?[7]	Indeterminate	Guimarota		Isolated Teeth and a partial skull
Pachycormidae[7]	Indeterminate	Guimarota

Amphibians

Albanerpetontids are one of the most numerous faunal components of the Guimarota mine with around 9000 isolated remains, including parts of the skull and limbs. Remains of indeterminate salamanders and frogs are also present but far rarer.^[7]

Amphibians of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
cf. Celtedens[7]	Indeterminate	Porto Pinheiro			Albanerpetontid
cf. Marmorerpeton[7]	Indeterminate	Guimarota			Indeterminate salamander
Discoglossidae[7]	Indeterminate	Guimarota			Indeterminate frog

Choristoderes

Choristoderes of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Cteniogenys	Indeterminate	Guimarota

Ornithischians

Indeterminate euornithopod remains located in Lisbon District.^[5] Indeterminate stegosaurid remains present in Lisbon District.^[5]

Ornithischians of the Alcobaça Formation
Genus	Species	District	Stratigraphic position	Abundance	Notes	Images
Dacentrurus[5]	D. armatus[5]	Lisboa[5]
Eousdryosaurus[8]	E. nanohallucis	Lisboa[5]
Stegosaurus[9]	S. cf. ungulatus				"...one tooth, five cervical vertebrae (including the axis), five dorsal vertebrae, cervical and dorsal ribs, three caudal vertebrae, chevrons, preacetabular process of the left ilium, right tibia, fibula, astragalus and [calcaneus], a cervical plate, and several fragments of plates."
Trimucrodon[5]	T. cuneatus[5]	Lisboa[5]			Later determined to be indeterminate ornithischian remains.[5]

Saurischians

Indeterminate sauropod remains located in Leiria and Lisboa.^[10]

Saurischians of the Alcobaça Formation
Genus	Species	District	Stratigraphic position	Abundance	Notes	Images
Allosaurus[6]	A. europaeus[11]	Leiria[6]		A partial skeleton (MNHNUL/AND.001) including parts of the skull.[11]
Aviatyrannis	A. jurassica	Guimarota
Lusotitan[5]	L. atalaiensis[5]	Lisboa[5]
Ceratosaurus[5]	Indeterminate[5]	Lisboa[5]
Dinheirosaurus[5]	D. lourinhanensis[5]	Lisboa[5]		"[Two] cervicals, [nine] dorsals, ribs, limb elements."[12]
Lourinhasaurus[5]	L. alenquerensis[5]	Lisboa[5]
Megalosaurus[5]	M. insignis[5]	Lisboa[5]			Later determined to be indeterminate theropod remains.[5]

Pterosaurs

Pterosaurs of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
aff. Rhamphorhynchus[7]	Indeterminate	Guimarota		Isolated Fragments
Pterodactyloidea[7]	Indeterminate	Guimarota		Teeth

Turtles

Turtles of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Peltochelys	P. duchastelli	Guimarota
Platychelys	Indeterminate	Guimarota
Pleurosternidae	Indeterminate	Guimarota

Lepidosauromorphs

Lepidosauromorphs of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Becklesius	B. hoffstetteri	Guimarota			Paramacellodid lizard
Dorsetisaurus	D. purbeckensis	Guimarota			Anguimorph lizard
Marmoretta[13]	M. drescherae	Guimarota			Basal Lepidosauromorph
Portugalophis	P. lignites	Guimarota			Stem-snake
Saurillodon	S. proraformis	Guimarota			A lizard
Saurillus	S. henkeli, cf. obtusus	Guimarota			A lizard
cf. Opisthias[14]	Indeterminate	Andrés, Pombal			A rhynchocephalian

Crocodyliformes

Crocodyliformes of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Goniopholis	G. baryglyphaeus	Guimarota			A goniopholidid
Knoetschkesuchus	K. guimarotae	Guimarota			An atoposaurid
Lisboasaurus	L. mitracostatus	Guimarota
Machimosaurus	M. hugii	Guimarota			A marine machimosaurid

Mammals

Mammals of the Alcobaça Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bathmochoffatia	B. hapax	Guimarota			A paulchoffatiid multituberculate
Bernardodon	B. sp, B. atlanticus	Porto Pinheiro			A pinheirodontid multituberculate
Drescheratherium	D. acutum	Guimarota			A paurodontid dryolestidan
Dryolestes	D. leirensis	Guimarota			A dryolestid dryolestidan
Ecprepaulax	E. anomala	Porto Pinheiro			A pinheirodontid multituberculate
Guimarotodon	G. leiriensis	Guimarota			A paulchoffatiid multituberculate
Guimarotodus	G. inflatus	Guimarota			A dryolestid dryolestidan
Haldanodon	H. exspectatus	Guimarota			A docodont
Henkelodon	H. naias, H. sp	Guimarota			A paulchoffatiid multituberculate
Henkelotherium	H. guimarotae	Guimarota			A dryolestidan
Iberodon	I. quadrituberculatus	Porto Pinheiro			A pinheirodontid multituberculate
Kielanodon	K. hopsoni	Guimarota			A paulchoffatiid multituberculate
Krebsotherium	K. lusitanicum	Guimarota			A dryolestid dryolestidan
Kuehneodon	K. guimarotensis, K. dietrichi, K. simpsoni, K. uniradiculatus, K. sp	Guimarota			A paulchoffatiid multituberculate
Laolestes	L. andresi	Porto Pinheiro			A dryolestid dryolestidan
Meketibolodon	M. robustus	Guimarota			A paulchoffatiid multituberculate
Meketichoffatia	M. krausei, M. sp	Guimarota			A paulchoffatiid multituberculate
Nanolestes	N. krusati	Porto Pinheiro			A cladotherian
	N. drescherae	Guimarota
Paulchoffatia	P. delgadoi	Guimarota			A paulchoffatiid multituberculate
Pinheirodon	P. sp, P. vastus, P. pygmaeus	Porto Pinheiro			A pinheirodontid multituberculate
Plesiochoffatia	P. thoas, P. peperethos	Guimarota			A paulchoffatiid multituberculate
Portopinheirodon	P. asymmetricus	Porto Pinheiro			A dryolestid dryolestidan
Priacodon	Indeterminate	Porto Pinheiro			A triconodontid
Proalbionbaatar	P. plagiocyrtus	Guimarota			A multituberculate of uncertain placement
Pseudobolodon	P. dryas, P krebsi, P. oreas	Guimarota			A paulchoffatiid multituberculate
Renatodon	R. amalthea	Guimarota			A paulchoffatiid multituberculate
? Tinodon	Indeterminate	Porto Pinheiro			A tinodontid symmetrodont
Xenachoffatia	X. oinopion	Guimarota			A paulchoffatiid multituberculate
Paulchoffatiidae	Indeterminate	Guimarota			4 distinct genera with 7 species
Pinheirodontidae	Indeterminate	Porto Pinheiro

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.

Invertebrate Paleofauna

Ostracods

Ostracods of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Cetacella[7]	C. armata				Cetacella is a typical component of Late Jurassic brackish water environments in Europe. Member of the Cypridacea[7]
	C. inermis
	C. striata
Theriosynoecum[7]	T. wyomingense				Member of the Cytheracea
Bisulcocypris[7]	B. pahasapensis				Member of the Cytheracea
Timiriasevia[7]	T. guimarotensis				Member of the Cytheracea
Poisia[7]	P. bicostata				Member of the Cytheracea
	P. clivosa
Dicrorygima[7]	D. reticulata				Member of the Cytheracea
Darwinula[7]	D. leguminella				Member of the Darwinulacea

Mollusca

Bivalves

Bivalves of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Isognomon[7]	I. rugosus	Guimarota		Dozens of well preserved shells sometimes making up entire stratigraphic layers	This genus is regarded as an indicator for brachyhaline water conditions and it was likely buried in its natural habitat[7]
"Unio"	"U." cf. alcobacensis	Guimarota		Dozens of well preserved shells with articulated valves	freshwater clam

Gastropods

Gastropods of the Alcobaça Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Teinostoma[7]	Indeterminate	Guimarota		Shells	Boring traces of clionidid sponges on the shells of this taxon indicate a marine lifestyle[7]
Cryptaulax[7]	Indeterminate	Guimarota		Shells
Melampoides[7]	M. jurassicus	Guimarota		Shells	Boring traces of clionidid sponges on the shells of this taxon indicate a marine lifestyle, modern relatives like Melampus also venture onto land, which can also be expected from M. jurassicus[7]

See also

• List of dinosaur-bearing rock formations
• List of fossiliferous stratigraphic units in Portugal