Lourinhã Formation

The Lourinhã Formation (Portuguese pronunciation: [loɾiˈɲɐ̃] ^ⓘ) is a fossil-rich geological formation in western Portugal, named for the municipality of Lourinhã. The formation is mostly Late Jurassic in age (Kimmeridgian/Tithonian), with the top of the formation extending into the earliest Cretaceous (Berriasian). It is notable for containing a fauna especially similar to that of the Morrison Formation in the United States and a lesser extent to the Tendaguru Formation in Tanzania. There are also similarities to the nearby Villar del Arzobispo Formation and Alcobaça Formation. Besides the fossil bones, Lourinhã Formation is well known for the fossil tracks and fossilized dinosaur eggs.^[1][2]

Lourinhã Formation
Stratigraphic range: late Kimmeridgian-earliest Berriasian ~152.5–144.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Sub-units	Consolação Sub-Basin - Praia da Amoreira-Porto Novo Member, Praia Azul Member, Santa Rita Member Turcifal Sub-Basin - Assenta Member
Underlies	Porto da Calada Formation
Overlies	Consolação & Alcobaça Formations
Thickness	200–1,100 metres (660–3,610 ft)
Lithology
Primary	Sandstone, mudstone, marl
Other	Conglomerate, limestone
Location
Coordinates	39.23°N 9.32°W / 39.23; -9.32
Region	Lisbon Region
Country	Portugal
Extent	Lusitanian Basin
Type section
Named for	Lourinhã
Named by	Hill
Year defined	1988
Lourinhã Formation (Portugal)

The Lourinhã Formation includes several lithostratigraphic units, such as Praia da Amoreira-Porto Novo Members, Praia Azul Member, the Santa Rita Member, and the Assenta Member.^[3] The stratigraphy of the formation is complex and controversial, with the constituent member beds belonging to the formation varying between different authors.^[4]

Lithology and depositional history

Depositional history

Location of the Lusitanian basin within the Iberian Peninsula

The Lourinhã Formation is located within the Lusitanian Basin, a mostly onshore North South orientated rift basin within western Portugal, formed during the Opening of the North Atlantic Ocean, with sediment deposition beginning during the Late Triassic-Early Jurassic. It primarily consists of syn-rift near-coastal continental siliciclastic sediments, with several marine intercalations. The primary flow direction was North to South, originating from Galicia and flowing between the Iberian landmass to the east and the now largely submerged Berlengas horst, a north–south oriented ridge, to the west.

Stratigraphy

The unit was first formally proposed by Hill in 1988.

The stratigraphy of the Lourinhã Formation is complex and varies between sub-basins with several competing stratigraphic proposals and there is currently no consensus on the matter, one of the most recent stratigraphies,^[4] divides the formation into three members which are from oldest to youngest the Praia da Amoreira-Porto Novo Member, Praia Azul Member, and the Assenta Member.

Praia da Amoreira-Porto Novo Member

The Praia da Amoreira-Porto Novo Member is composed of the Priaia de Amoreira Member, which consists of massive mudrock-sand with metre thick sandstone lenses, with massive mudrock with calcrete. The overlying Poto Novo Mb. consists of massive bodies of sandstone, often cross bedded. The environment of deposition is interpreted as a meandering fluvial system, while the Porto Novo Mb is interpreted as a deltaic deposit. It is interpreted to be latest Kimmeridgian in age, and overlies the Consolacao Unit at the top of the Aulacostephanus eudoxus ammonite zone.^[4][5]

Praia Azul Member

The Praia Azul Member, formerly known as the Sobral unit/member is 80 to 130 metres thick and consists of tabular marls and mudstones, with rare sandstones bodies. There are three distinct laterally extensive (>20 km) thin shelly carbonate horizons within this member, indicating brief marine transgressions. South of Santa Cruz primarily consists of sandstone with rare conglomerate. The age is considered to be latest Kimmeridgian to earliest Tithonian, correlated to the ammonite zones of Hybonoticeras beckeri and Hybonoticeras hybonotum.^[4][5]

Santa Rita Member + Assenta Member

The Santa Rita Member in the Consolação sub-basin and its lateral equivalent in the Turcifal Basin the Assenta Member is around 300 metres thick and predominantly consists of mudstones with frequent layers of caliche. Near the top of the member several layers of tens of metres thick nodular and marly bioclastic limestones are present, containing marine benthic forams, the nodularity is derived from intense Thalassinoides burrowing. It is predominately late Tithonian in age, with the last few metres probably being earliest Berriasian, with the top of the formation roughly correlative with the base of the magnetochron M18n. (~144.7 Ma)^[6][4] The environment of deposition is interpreted as being an upper fluvial-dominated delta to meandering fluvial systems flowing on a paralic plain.

Fauna

Dinosaurs

In a 2003 study, an analysis of all Portuguese dinosaurs was published. The study created a cladogram showing the possible relations of all Portuguese dinosaurs, including those at the time known from the Lourinhã Formation.^[7]

Dinosauria

Ornithischia Thyreophora Lusitanosaurus Eurypoda Dacentrurus Dracopelta Ornithopoda "Fabrosaurids" Alocodon Trimucrodon Taveirosaurus Euornithopoda Hypsilophodontidae Hypsilophodon Phyllodon Ankylopollexia Dryosaurus Draconyx Camptosaurus Saurischia Sauropoda Dinheirosaurus Macronaria Lourinhasaurus Pleurocoelus Lusotitan Theropoda Ceratosaurus Tetanurae Torvosaurus Lourinhanosaurus Allosaurus Coelurosauria Compsognathus Stokesosaurus Maniraptora Richardoestesia Euronychodon Paronychodon Aves

Ornithischia

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.

Ornithopods

Genus	Species	Member	Material	Notes	Images
Ankylopollexia indet.[8]	Indeterminate	Praia Azul Member Santa Rita Member	Appendicular, axial, and cranial elements
Camptosaurus[9]	Intermediate[9]		Limb material[9]	Now referred to its own genus, Draconyx, along with some other material.[9]
Draconyx[9]	D. loureiroi[9]	Praia Azul Member[10]	One partial skeleton[10]
Dryosauridae indet.[8]	Indeterminate	Praia Azul Member	Appendicular, axial, and cranial elements
Dryosaurus[7]	D. sp.[7]	Praia Azul Member			Dryosaurus
Eousdryosaurus[11]	E. nanohallucis[11]	Praia da Amoreira-Porto Novo Formation[11]	A partial postcranial skeleton.
Hesperonyx[12]	H. martinhotomasorum	Porto Novo Member	Bones from the fore- and hindlimbs	A dryomorphan iguanodontian with uncertain affinities
Ornithopoda indet.[13]	Intermediate[13]		A single track[13]	Gigantic track indicating an ornithopod with a hip height of 2.5 meters. No known Jurassic Ornithopod reaches this size; only known evidence for such sizes in this group at the time. Found alongside Deltapodus print.[13]
Phyllodon[7]	P. henkelli.[7]		Two teeth

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.

Thyreophorans

Genus	Species	Member	Material	Notes	Images
Dacentrurus[14]	D. armatus[14]	Santa Rita Member[15] Praia Azul Member[15]		A stegosaurid, material referred to Miragaia may represent this taxon
Deltapodus[16]	D. brodricki[16]		Eleven tracks; Nine pes and two manus prints.[16]	The tracks can be separated into three different morphologies, though all fall within range of the Ornithopodsociation of the pes and manus tracks to the same taxon cannot be directly supported. Preserve various well preserved skin impressions. Largest prints are larger than those from the type horizon. The tracks are individually represented and do not form any sort of trackway, thought one print is associated with giant ornithopod track,[13] potentially representing that the creatures were traveling together or were otherwise going to a similar location. Another is similarly associated with theropod and sauropod prints.[16]
Dracopelta[7]	D. zbyszewskii[7]	Assenta Member		An ankylosaur.
Miragaia[17]	M. longicollum[17]	Santa Rita Member[15] Praia Azul Member[15]	Holotype, neck, partial skull, forelimbs, ribs. Tentative juvenile specimen assigned to this taxon.[17]	Stegosaur with unusually long neck of 17 cervicals, with more neck vertebrae than most sauropods.[17] Probably a junior synonym of Dacentrurus.[18][19]

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.

Other Ornithiscians

Genus	Species	Member	Material	Notes	Images
Trimucrodon[7]	T. cuneatus[7]	Amoreira-Porto Novo Member[20]	3 isolated teeth.
Alocodon[7]	A. kuehnei[7]

Saurischia

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.

Sauropods

Genus	Species	Member	Material	Notes	Images
Dinheirosaurus[21]	D. lourinhanensis[21]	Praia da Amoreira-Porta Novo Member[21]	One specimen. Vertebrae; potentially other parts of the body.[21]	A diplodocid. Tschopp et al. (2015) sunk the genus into Supersaurus.[21]	Dinheirosaurus Lusotitan Zby
Diplodocidae indet.[22]	Intermediate[22]		One Dorsal Vertebra[22]	Regarded by Mannion et al. (2012) as being unique from Dinheirosaurus and possibly indicating another diplodocid in the formation, but being non-diagnostic it doesn't warrant description.[22]
Lourinhasaurus[23]	L. alenquerensis[23]	Praia Azul Member	A partial postcranial skeleton.	Possibly a Camarasaurid Macronarian.[23]
Lusotitan[24][25]	L. atalaiensis[24][25]	Praia Azul Member	Fragmentary material.[24]	A large brachiosaur, a close relative of Brachiosaurus proper.[24]
Oceanotitan	O. dantasi[26]	Praia da Amoreira-Porta Novo Member	scapula, almost all of the pelvis, a complete leg sans the toes, and nine caudals.	A titanosauriform
Zby[20]	Z. atlanticus[20]	Amoreira-Porto Novo Member[20]	Holotype: Tooth, cervical neutral arch, forelimb, various other fragments.[20]	A turiasaur.[20]

Theropods

Genus	Species	Member	Material	Notes	Images
Abelisauridae indet.[27]	Intermediate[27]	Praia da Amoreira-Porto Novo Member[4]	Teeth; ML 966, Ml 327.[27]	Potentially diagnostic abelisaur teeth.[27]
Allosaurus[28][29]	A. europaeus[28]	Praia Azul Member[4]	Two specimens, covering much of the body.[30]	Only European species of Allosaurus.	Allosaurus europaeus
	A. fragilis[29]	Praia Azul Member[4]	Two specimens, covering much of the body.[30]	Now thought to represent a specimen of A. europaeus.[28]
Ceratosaurus[28][31][32]	C. sp.[28][31]	Praia da Amoreira-Porto Novo Member[28][31][20]	Four specimens; teeth, a femur.[28][31]	Potentially a synonym of the type species, C. nasicornis. Sometimes referred to as C. sp., giving indication of possible distinctiveness or of being intermediate.[20]	Ceratosaurus
Dendroolithidae[2]	Indeterminant		Fragments of multiple eggs in a clutch, with associated embryonic remains.[2]	Probably eggs of Torvosaurus.[2]
Lusovenator[33]	L. santosi[33]	Praia de Amoreira Member[33] Assenta Member[33]	Two partial postcranial skeletons.[33]	Earliest known Carcharodontosaurian from Laurasia.[33]
Lourinhanosaurus[7][34]	L. antunesi[7][34]	Praia Azul Member[34]	Three individuals, one largely complete; over 100 eggs with significant amount of skeletal material.[34]	Has come out in various places in the tree, erroneously said to be a megalosaur,[28] mostly accepted to be a carnosaur, probably allosauroid, or basal coelurosaur. Currently unstable on the tree.[34]	Lourinhanosaurus Embryo
Megalosaurus[27]	M. insignis[27]		Teeth.[27]	Invalid. Teeth belong to various other theropod taxa.[27]
	M. pombali[27]		Teeth.[27]	Invalid. Teeth belong to various other theropod taxa[27]
	M. sp.[27]		Tooth fragment.[27]	Invalid; Dubious.[27]
Richardoestesia[27]	R. aff. gilmorei[27]		Tooth; ML 939[27]	Only definite record of this taxon is from the Late Cretaceous of North America, despite erroneous and referrals from other sites in Portugal. Probably a close relative of Richardoestesia and not an actual representation of the taxon.[27]
Torvosaurus[28][35]	T. gurneyi[35]	Praia da Amoreira-Porto Novo Member[35] Praia Azul Member?[36]	Maxilla, Teeth, Femur; Egg clutch and embryos.[2][28][35][37]	Largest known European theropod. Previous known as Portugal populations of the type species, or as T. sp., before description in early 2014.[35]	Skeletal restoration showing the size of T. gurneyi, known remains highlighted.
	T. tanneri[35]	Praia da Amoireira-Porto Novo[20][37]	Maxilla, Teeth, Femur; Probable embryo.[34][35]	Now described as a distinct species of Torvosaurus, T. gurneyi. Sometimes referred to as T. sp. in the past.[35]

Pterosaurs

Genus	Species	Member	Material	Notes	Images
Dsungaripteroidea indet.[38]	Indeterminate	Praia da Amoreira-Porto Novo Member	Proximal right femur	A very large femur of a basal dsungaripteroid
Rhamphorhynchidae[39]	Indeterminate		Tooth
Lusognathus	L. almadrava		Skull and cervical vertebrae	Ctenochasmatid
Pteraichnus[40]			Partial tracks

Mammaliaformes

Docodonta

Genus	Species	Member	Material	Notes
Haldanodon	Haldanodon expectatus		Partial skeleton and isolated bones	Semi-aquatic forager.

Cladotheria

Genus	Species	Member	Material	Notes
Nanolestes	Nanolestes drescherae		Right lower molar.	Amphitheriidae; small omnivore or insectivore.
Guimarotodus	Guimarotodus inflatus		Right mandible.	Dryolestidae; insectivore or omnivore.
Krebsotherium	Krebsotherium lusitanicum		Left mandible.	Dryolestidae; insectivore or omnivore.
Drescheratherium	Drescheratherium acutum		Upper jaw.	Paurodontidae; herbivore.

Multituberculata

Genus	Species	Member	Material	Notes
Kuehneodon	K. hahni			A member of the family Paulchoffatiidae

Amphibians

Genus	Species	Member	Material	Notes
Celtedens	Indeterminate	Porto Novo/Praia da Amoreira, Praia Azul	Frontal bones,[41] along with other parts of the skull and limbs[39]	An albanerpetontid.
Urodela[39]	Indeterminate		Atlas vertebra	A salamander, suggested to belong to Scapherpetontidae.
"Discoglossidae"[39]	Indeterminate		Partial left humerus	A primitive frog

Squamates

Genus	Species	Member	Material	Notes
Paramacellodidae[39]	Indeterminate		Frontal and dentary bones	Scincomorph lizard

Crocodyliformes

Genus	Species	Member	Material	Notes
Ophiussasuchus	O. paimogonectes	Praia Azul Member	Partial skull	Goniopholidid
Goniopholididae	Indeterminate		Teeth[42] and partial skeleton.[43]	An aquatic neosuchian
Bernissartiidae			Tooth[42]
Lusitanisuchus			Teeth, and partial skull and jaw fragments[42]	A mesoeucrocodylian of uncertain placement
Atoposauridae			Teeth[42]
Mesoeucrocodylia			Teeth[42]	Distinct from Lusitanisuchus

Fish

Genus	Species	Member	Material	Notes
Hybodus[44]	H. cf. reticulatus		Teeth	A hybodontid shark
Pycnodontiformes[39]	Indeterminate
Lepidotes sensu lato[39]				A ginglymodian
Caturus[39]				An amiiform

Flora

Genus	Species	Member	Material	Notes	Images
Pterophyllum	P. mondeguensis[45]			Bennettitales leaf
Otozamites[4]				Bennettitales leaf
Cupressinocladus[4]				Conifer leaves
Protocupressinoxylon[46]				Conifer wood
Prototaxoxylon[46]
Classopollis[4]				Pollen of Cheirolepidiaceae conifers

Correlation

Early Cretaceous stratigraphy of Iberia

Ma	Age	Paleomap \ Basins	Cantabrian	Olanyà	Cameros	Maestrazgo	Oliete	Galve	Morella	South Iberian	Pre-betic	Lusitanian
100	Cenomanian		La Cabana	Sopeira	Utrillas		Mosquerela					Caranguejeira
			Altamira		Utrillas
			Eguino
125	Albian		Ullaga - Balmaseda	Lluçà						Traiguera
			Monte Grande		Escucha		Escucha			Jijona
			Itxina - Miono
	Aptian		Valmaseda - Tellamendi		Ol Gp. - Castrillo	Benassal		Benassal				Olhos
				Font	En Gp. - Leza	Morella/Oliete	Oliete	Villaroya	Morella	Capas Rojas		Almargem
			Patrocinio - Ernaga	Senyús	En Gp. - Jubela	Forcall				Villaroya	Upper Bedoulian	Figueira
	Barremian		Vega de Pas	Cabó	Abejar	Xert	Alacón	Xert		Huérguina		Assises
				Prada		Artoles				Collado	Moutonianum	Papo Seco
				Rúbies	Tera Gp. - Golmayo	Alacón/Blesa	Blesa	Camarillas	Mirambel
150	Hauterivian				Ur Gp. - Pinilla	Llacova		Castellar	Tera Gp. - Pinilla	Villares		Porto da Calada
							hiatus
						Huerva			Gaita
	Valanginian		Villaro		Ur Gp. - Larriba				Ped Gp. - Hortigüela
					Ped Gp. - Hortigüela				Ped Gp. - Piedrahita
					Peñacoba			Galve		Miravetes
	Berriasian		Cab Gp. - Arcera		Valdeprado	hiatus		Alfambra
					TdL Gp. - Rupelo			Arzobispo	hiatus	Tollo
					On Gp. - Huérteles Sierra Matute
	Tithonian		Lastres		Tera Gp. - Magaña		Higuereles			Tera Gp. - Magaña		Lourinhã
									Arzobispo
					Ágreda
Legend		Major fossiliferous, oofossiliferous, ichnofossiliferous, coproliferous, minor formation
Sources

See also

• Camadas de Alcobaça
• Camadas de Guimarota
• List of fossil sites
• Museu da Lourinhã
• List of dinosaur bearing rock formations