Jurassic

Puértolas-Pascual, E., Marx M., Mateus O., Saleiro A., Fernandes A. E., Marinheiro J., Tomás C., & Mateus S. (2021).  A new plesiosaur from the Lower Jurassic of Portugal and the early radiation of Plesiosauroidea. Acta Palaeontologica Polonica. 66(2), 369-388. Abstracta_new_plesiosaur_from_the_lower_jurassic_of_portugal_and_the_early_radiation_of_plesiosauroidea.pdfWebsite

A new plesiosaur partial skeleton, comprising most of the trunk and including axial, limb, and girdle bones, was collected in the lower Sinemurian (Coimbra Formation) of Praia da Concha, near São Pedro de Moel in central west Portugal. The specimen represents a new genus and species, Plesiopharos moelensis gen. et sp. nov. Phylogenetic analysis places this taxon at the base of Plesiosauroidea. Its position is based on this exclusive combination of characters: presence of a straight preaxial margin of the radius; transverse processes of mid-dorsal vertebrae horizontally oriented; ilium with sub-circular cross section of the shaft and subequal anteroposterior expansion of the dorsal blade; straight proximal end of the humerus; and ventral surface of the humerus with an anteroposteriorly long shallow groove between the epipodial facets. In addition, the new taxon has the following autapomorphies: iliac blade with less expanded, rounded and convex anterior flank; highly developed ischial facet of the ilium; apex of the neural spine of the first pectoral vertebra inclined posterodorsally with a small rounded tip. This taxon represents the most complete and the oldest plesiosaur species in the Iberian Peninsula. It is also the most complete, best preserved, and oldest marine vertebrate in the region and testifies to the incursion of marine reptiles in the newly formed proto-Atlantic sea, prior to the Atlantic Ocean floor spreading in the Early Cretaceous.

Puértolas-Pascual, E., & Mateus O. (2019).  A three-dimensional skeleton of Goniopholididae from the Late Jurassic of Portugal: implications for the Crocodylomorpha bracing system. Zoological Journal of the Linnean Society. , 10 Abstractpuertolas-pascual__mateus_2019_croc.pdfWebsite

{We here describe an articulated partial skeleton of a small neosuchian crocodylomorph from the Lourinhã Formation (Late Jurassic, Portugal). The skeleton corresponds to the posterior region of the trunk and consists of dorsal, ventral and limb osteoderms, dorsal vertebrae, thoracic ribs and part of the left hindlimb. The paravertebral armour is composed of two rows of paired osteoderms with the lateral margins ventrally deflected and an anterior process for a ‘peg and groove’ articulation. We also compare its dermal armour with that of several Jurassic and Cretaceous neosuchian crocodylomorphs, establishing a detailed description of this type of osteoderms.These features are present in crocodylomorphs with a closed paravertebral armour bracing system. The exceptional 3D conservation of the specimen, and the performance of a micro-CT scan, allowed us to interpret the bracing system of this organism to assess if previous models were accurate. The characters observed in this specimen are congruent with Goniopholididae, a clade of large neosuchians abundant in most semi-aquatic ecosystems from the Jurassic and Early Cretaceous of Laurasia. However, its small size, contrasted with the sizes observed in goniopholidids, left indeterminate whether it could have been a dwarf or juvenile individual. Future histological analyses could shed light on this.}

Ribeiro, V., & Mateus O. (2012).  Chronology of the Late Jurassic dinosaur faunas, and other reptilian faunas, from Portugal. Journal of Vertebrate Paleontology, Program and Abstracts, 2012, p. 161 ISSN 1937-2809. ribeiro__mateus_2012_chronology_dinosaurs_portugal_abstract_book_meeting_abstracts.pdf.pdf
Myers, T. S., Tabor N. J., Jacobs L. L., & Mateus O. (2012).  Estimating soil pCO2 using paleosol carbonates: implications for the relationship between primary productivity and faunal richness in ancient terrestrial ecosystems. Paleobiology. 38(4), 585–604. Abstractmyers_et_al_2012_estimating_soil_paleosols_portugal.pdf

In this paper we present a method for estimating soil pCO2 in ancient environments using the measured carbon-isotope values of pedogenic carbonates and plant-derived organic matter. The validity of soil pCO2 estimates proves to be highly dependent on the organic δ13C values used in the calculations. Organic matter should be sourced from the same paleosol profiles as sampled carbonates to yield the most reliable estimates of soil pCO2. In order to demonstrate the potential use of soil pCO2 estimates in paleoecological and paleoenvironmental studies, we compare samples from three Upper Jurassic localities. Soil pCO2 estimates, interpreted as a qualitative indicator of primary paleoproductivity, are used to rank the Late Jurassic terrestrial environments represented by the Morrison Formation in western North America, the informally named Lourinhã formation in Western Europe, and the Stanleyville Group in Central Africa. Because modern terrestrial environments show a positive correlation between primary productivity and faunal richness, a similar relationship is expected in ancient ecosystems. When the relative paleoproductivity levels inferred for each study area are compared with estimates of dinosaur generic richness, a positive correlation emerges. Both the Morrison and Lourinhã formations have high inferred productivity levels and high estimated faunal richness. In contrast, the Stanleyville Group appears to have had low primary productivity and low faunal richness. Paleoclimatic data available for each study area indicate that both productivity and faunal richness are positively linked to water availability, as observed in modern terrestrial ecosystems.

Mateus, O. (2008).  Checklist for Late Jurassic reptiles and amphibians from Portugal. Livro de Resumos do X Congresso Luso-Espanhol de Herpetologia. 55., Coimbra Abstractmateus_2008_lista_de_repteis_e_anfibios_do_jurassico_superior_de_portugal__list_congressoherpetolog.pdf

The richness of Late Jurassic vertebrates in Portugal is known since the 19th century by Paul Choffat, Henri Sauvage and other. The Kimmeridgian Guimarota fauna assemblage is the best known, followed by the fauna of Lourinhã formation. Here is presented an attempt to provide a checklist of the reptiles and amphibians of the Late Jurassic. Amphibia: Lissamphibia (Celtedens, cf. Marmorerpeton, Discoglossidae indet.). Chelonia: Eucryptodira (Pleurosternidae indet., Platychelyidae indet., Plesiochelys cf. etalloni, Plesiochelys choffati, Anosteirinae indet.). Squamata: Scincomorpha (Becklesius hoffstetteri; Paramacellodus sp., Saurillodon proraformis, S. henkeli, S. cf. obtusus). Squamata: Anguimorpha (Dorsetisaurus pollicidens, Parviraptor estesi). Crown Lepidosauromorpha (Marmoretta sp.). Choristodera: Cteniogenidae (Ctenogenys reedi). Sauropterygia: Plesiosauria: Cryptoclidoidea: Cryptoclididae indet. Crocodylomorpha (Lisboasaurus estesi, L. mitrocostatus). Crocodyliformes: Neosuchia (Machimosaurus hugii, Goniopholis cf. simus, Goniopholis baryglyphaeus, cf. Bernissartia, Atoposauridae, Theriosuchus guimarotae, cf. Alligatorium, Metriorhynchus sp.). Pterosauria (Rhamphorhynchus sp., Pterodactylus sp.). Dinosauria: Theropoda (Ceratosaurus sp. , Torvosaurus sp., Lourinhanosaurus antunesi, Allosaurus europaeus, Cf. Compsognathus sp., cf. Richardoestesia sp., Dromaeosaurinae indeter., Velociraptorinae indeter., cf. Archaeopteryx sp., aff. Paronychodon). Dinosauria: Sauropoda: Eusauropoda (Dinheirosaurus lourinhanensis, Lourinhasaurus alenquerensis, Lusotitan atalaiensis, Apatosaurus sp.). Dinosauria: Ornithischia: Thyreophora (Dacentrurus armatus, Stegosaurus sp., Dracopelta zbyszewskii). Dinosauria: Ornithischia: Ornithopoda (Phyllodon henkeli, Dryosaurus sp., Hypsilophodon sp., Alocodon kuehnei, Trimucrodon cuneatus, Draconyx loureiroi).

Mateus, O., & Antunes M. T. (2000).  Ceratosaurus sp. (Dinosauria: Theropoda) in the Late Jurassic of Portugal. Abstract volume of the 31st International Geological Congress. , Rio de Janeiro, Brazil Abstractmateus__antunes_2000_-_ceratosaurus_in_portugal.pdf

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Mateus, O., Laven T., & Knotschke N. (2004).  A dwarf between giants? A new late Jurassic sauropod from Germany. Journal of Vertebrate Paleontology. 23, 90A., Number suppl. to 3mateus_et_al_2004_a_dwarf_between_giants-_a_new_late_jurassic_sauropod_from_germany_svp.pdfWebsite
Mateus, O., & Antunes T. M. (2001).  Draconyx loureiroi, a new camptosauridae (Dinosauria, Ornithopoda) from the Late Jurassic of Lourinhã, Portugal. Annales de Paleontologie. 87, 61-73. Abstractmateus_antunes_2001_draconyx_loureiroi_a_new_camptosauridae_dinosauria_ornithopoda_from_the_late_jurassic_of_lourinha_portugal.pdfWebsite

A new ornithopod dinosaur is described here under the name of Draconyx loureiroi n. gen., n. sp. on teeth, caudal vertebrae, forelimb, hindlimb, and foot material that were found in association in the Late Jurassic-Tithonian of Lourinhã, Portugal. Draconyx is a Camptosauridae related to Camptosaurus.

Myers, T. S., Tabor N. J., Jacobs L. L., & Mateus O. (2012).  Palaeoclimate of the Late Jurassic of Portugal: Comparison with the Western United States. Sedimentology. 59(6), 1695–1717., 2012//01/ Abstractmyers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_with_the_western.pdfWebsite

Investigation of the palaeoclimatic conditions associated with Upper Jurassic strata in Portugal and comparison with published palaeoclimate reconstructions of the Upper Jurassic Morrison Formation in western North America provide important insights into the conditions that allowed two of the richest terrestrial faunas of this period to flourish. Geochemical analyses and observations of palaeosol morphology in the informally named Upper Jurassic Lourinhã formation of western Portugal indicate warm and wet palaeoclimatic conditions with strongly seasonal precipitation patterns. Palaeosol profiles are dominated by carbonate accumulations and abundant shrink-swell (vertic) features that are both indicative of seasonal variation in moisture availability. The δ18OSMOW and δDSMOW values of phyllosilicates sampled from palaeosol profiles range from +22·4‰ to +22·7‰ and −53·0‰ to −37·3‰, respectively. These isotope values correspond to temperatures of formation between 32°C and 39°C ± 3°, with an average of 36°C, which suggest surface temperatures between 27°C and 34°C (average 31°C). On average, these surface temperature estimates are 1°C higher than the highest summer temperatures modelled for Late Jurassic Iberia using general circulation models. Elemental analysis of matrix material from palaeosol B-horizons provides proxy (chemical index of alteration minus potassium) estimates of mean annual precipitation ranging from 766 to 1394 mm/year, with an average of approximately 1100 mm/year. Palaeoclimatic conditions during deposition of the Lourinhã formation are broadly similar to those inferred for the Morrison Formation, except somewhat wetter. Seasonal variation in moisture availability does not seem to have negatively impacted the ability of these environments to support rich and relatively abundant faunas. The similar climate between these two Late Jurassic terrestrial ecosystems is probably one of the factors which explains the similarity of their vertebrate faunas.