Two new theropod egg sites from the Late Jurassic Lourinhã Formation, Portugal

Ribeiro, V., Mateus O., Holwerda F., Araújo R., & Castanhinha R. (2014).  Two new theropod egg sites from the Late Jurassic Lourinhã Formation, Portugal. Historical Biology. 26(2), 206-217.


Two new Late Jurassic (uppermost Late Kimmeridgian) dinosaur eggshell sites are described, Casal da Rola and Porto das Barcas, both near Lourinha˜, central-west Portugal. Casal da Rola yields eggshells with an obliquiprismatic morphotype comparable to those from a nest with the associated fossil embryos from Paimogo, tentatively assigned to the theropod Lourinhanosaurus antunesi. The Porto das Barcas eggshells have a dendrospherulitic morphotype with a prolatocanaliculate pore system. This morphotype was also recognised in eggshells from a clutch with associated Torvosaurus embryos at the Porto das Barcas locality. A preliminary cladistic analysis of eggshell morphology suggests theropod affinities for the Casal da Rola eggs, but is unable to resolve the phylogenetic position of the Porto das Barcas eggs. The eggshells at both sites are preserved in distal flood plain mudstones and siltstones. Carbonate concretions within the deposits indicate paleosol development.

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Although many dinosaur eggs and eggshells are known from the Cretaceous, they are relatively rare in older deposits (e.g. Hirsch 1989; Mikhailov 1997). Jurassic egg sites are known from the Late Jurassic of the USA (Hirsch 1994; Turner and Peterson 2004), the Middle Jurassic of France (Garcia et al. 2006) and the Early Jurassic of South Africa (Kitching 1979; Zelenitsky and Modesto 2002; Reisz et al. 2012) and China (Reisz et al. 2013). Older egg sites are known only from the Late Triassic of Argentina
(Bonaparte and Vice 1979).
The Lourinha˜ region, in central-west Portugal, is rich in Late Jurassic dinosaur nest sites and well-preserved eggs. 
Several Kimmeridgian–Tithonian localities have been reported (Kohring 1993; Mateus et al. 1997; Antunes et al. 1998; Mateus, Mateus,Antunes, et al. 1998;Mateus, Taquet,
Antunes, et al. 1998; Castanhinha et al. 2008, 2009; Arau´jo et al. 2013). These discoveries increase the diversity of nesting environments in which eggs have been discovered, expand the disparity of morphotypes known from the
Lourinha˜ Formation and, most importantly, provide valuable information on the poorly known pre-Cretaceous egg fossils. This article aims to taxonomically assign and
describe fossil eggshells from two sites in the Lourinha˜ area: Porto das Barcas and Casal da Rola (general coordinates are 39.2N, 9.3W). In the area, direct connections between eggs and embryos are known from two sites, both attributable to
theropods: the Lourinhanosaurus nest from Paimogo (Mateus et al. 1997, 2001; Mateus, Mateus, Antunes, et al. 1998; Mateus, Taquet, Antunes, et al. 1998; de Ricqle`s et al.
2001; Cunha et al. 2004; Castanhinha et al. 2008, 2009) and the Torvosaurus egg clutch from Porto das Barcas (Arau´jo et al. 2013). Fossil evidence of theropods from the area
includes Ceratosaurus (Mateus and Antunes 2000a), Torvosaurus (Mateus and Antunes 2000b), Aviatyrannis jurassica Rauhut (2003), Allosaurus europaeus Mateus
et al., 2006, Lourinhanosaurus antunesi Mateus, 1998, Richardoestesia (Hendrickx and Mateus, 2013), plus an unknown genus of Abelisauridae (Hendrickx and Mateus
2013) as well as many others such as Troodontidae (Zinke 1998), and open nomenclature genera cf. Archaeopteryx (Weigert 1995), cf. Compsognathus, cf. Dromaeosaurus (Zinke 1998).

Materials and methods
Well-preserved eggshell specimens were selected from both localities (Casal da Rola, ML1194, only eggshells, and Porto das Barcas, ML1842, one fossil egg and the
corresponding eggshells) and cleaned using 10% hydrogen peroxide and either an ultrasound bath or a soft brush. 
Selected samples were prepared for 30-mm thin sections, using epoxy resin EpoThin 5 (resin) and 1.95 (hardener), for radial and tangential sections. We made two tangential 

and two radial thin sections of the Casal da Rola specimens
and four tangential and three radial thin sections of the
Porto das Barcas specimens. Pictures were taken using a
polarised light microscope (PLM) Labomed CXL POL
and a Leica CLS 100 £ binocular microscope.
The inner and outer surfaces of eggshell fragments
were imaged using a JEOL JSM T330A scanning electron
microscope (SEM) at the Universidade Nova Lisboa
(FCT-UNL). Fragments were also cut radially, polished
and then etched with 10% formic acid for 30 s to provide a
better view of the radial surface.
In order to measure the pore dimensions of the
eggshells, pictures were taken using binocular and macro
lenses. The diameter of each pore was measured with
GIMP 2.8.2 image software in order to determine pore area and total pore area against total sample area. Traditionally, eggshell fragments are used to estimate eggshell curvature, which in turn provides an estimate of overall egg size (Sauer 1968; Williams 1981). The methodology employed here is slightly different. This technique is based on the assumption that the arithmetic mean radius of an ellipsoid should be the same as the measured mean radius of the eggshell samples. On Casal da Rola eggshells, three measurements were taken on each eggshell fragment (N ¼ 27) with a digital caliper
(error ^ 5 mm): eggshell thickness (t) and the width (W) and height (h) across an orthogonal plane at the longest dimension of the eggshell fragment (see Figure 1). In order to get the arc height (H), the thickness of the eggshell (t) is subtracted from the measured height (h). The radius of curvature (R) of an arc is given by R ¼
: ð1Þ
To approximate the shape of the egg, we compared a sphere with mean radius R to produce a prolate ellipsoid with a mean radius r, the semi-axes (a, b) being dependent
on the elongation index (EL) 

Geology and age
Upper Jurassic strata in the Lusitanian Basin record a
marine to terrestrial syn-rift succession, where the
depositional systems were controlled by basin setting
and synsedimentary tectonic activity (Leinfelder 1993). In the Lourinha˜ region (Figure 2), the informally established Lourinha˜ Formation (Hill 1989) is a continental, siliciclastic and regressive unit that is dominated by fluvial sequences with occasional marine incursions (Pena dos Reis et al. 2000). The Lourinha˜ Formation spans the 
Kimmeridgian and Tithonian, possibly extending into the Berriasian (Alves et al. 2003).
A transgressive event during the Late Kimmeridgian to Early Tithonian led to the deposition of the Sobral Member, which has a total thickness of around 80m and
shows three distinctive marly layers with characteristic brackish water fauna throughout (Figure 3). The razorshaped bivalve Gervillia sobralensis Sharpe, 1850 is restricted to the base of the member (Leinfelder 1986). 
About half-way up the Sobral Member, a maximum flooding surface is recognised with Protocardia gigantea Schneider et al., 2010, a species restricted to this layer
and basin, known as the Kimmeridgian–Tithonian boundary based on Sr-isotope stratigraphy (Schneider et al. 2010).
At the top of the Sobral Member, the occurrence of the trigoniidae bivalve Myophorella lusitanica Sharpe, 1850 is restricted to the southern Arranho´ II Member which is of
Early Tithonian age (Schneider et al. 2008).
The locality of Casal da Rola was discovered in 1997 about 1 km south of Lourinha˜. The approximately 10-mthick section consists of marls containing G. sobralensis, Eomiodon securiformis Sharpe, 1850 and Isognomon lusitanicus Sharpe, 1850 at the base. The layer containing the eggshells is underlain by mudstones, siltstones and a fine-grained sandstone unit. The egg bed consists of mudstone and siltstone with carbonate concretions.

Some eggshell clusters are preserved within a carbonate matrix. No whole eggs were recovered since all shell fragments were obtained by surface collection and sieving. The taxonomic composition of the bivalve assemblage indicates that the site is located at the base of Sobral Member.
The Porto das Barcas locality also lies near Lourinha˜. The fossil egg material lay embedded in an isolated sandstone block from a sandstone layer in the above lying cliffs, which overlies an erosive and transgressive surface marked by I. lusitanicus and G. sobralensis bivalves, and in turn is overlain by a channel bed. The Kimmeridgian–Tithonian boundary is recognisable at the top of the 40-m cliff, so the egg-bearing unit is Late Kimmeridgian. Both the Casal da Rola and Porto das Barcas localities are coeval.

Dinosauria Owen, 1842
Theropoda Marsh, 1881
Oofamily PRISMATOOLITHIDAE Hirsch, 1994
Original diagnosis after Hirsch (1994)
Dinosauroid prismatic basic type morphotype, prismatic morphotype obliquicaniculate or angusticaniculate pore system. Outer shell surface smooth to undulating. Elongate
ellipsoid or ovoid eggs. Medium shell thickness 0.8–1.0 mm.
Oogenus Preprismatoolithus Zelenitsky and Hill, 1996
Original diagnosis after Zelenitsky and Hill (1996)
Dinosauroid basic type; angustiprismatic to obliquiprismatic
morphotype; obliquicaniculate or angusticaniculate

pore system; outer surface smooth to undulating or with
fine sculpturing; eggshell thickness 0.3–1.22 mm; eggs are
elongate, ellipsoidal or oval shaped; E ¼ 1.8–2.7.
Age and formation
Late Kimmeridgian, Lourinha˜ Formation, lower part of
Sobral Member

Material and taphonomy
Hundreds of eggshell fragments (ML1194) were found in a
siltstone layer in a steep cliff under dense vegetation.
Therefore, only loose fragments were collected at the
surface or by sieving. No preserved egg structures or
embryo remains were found.
Casal da Rola, Lourinha˜, Portugal.
External surface is smooth with sparse nodes. In the inner
surface of well-preserved samples, complete mammillary
units are visible (Figures 4(A),(C),(D),(F), 6(A)). The
eggshell thickness is 0.87mm [standard deviation (SD) ^ 0.06; N ¼ 27]. Under PLM, a mammillary zone is well defined, accounting for 1/3 to 1/4 of the eggshell thickness. The mammillary units measure 250–350 mm in height and change gradually upwards into a prismatic layer, with a columnar extinction pattern visible under polarised light (Figure 4(B)). In radial view, horizontal growth lines are also visible (see Figure 4(B); gl). Under a
microscope, a third zone of variable thickness is also visible (Figure 4(B); dl), consisting of recrystallised or secondary deposits, which also appear inside the pores, parts of the inner surface, or even on the edges of the eggshell. We interpret this extra layer as calcite, given that the eggshells themselves are composed of calcite, and they are preserved in carbonate-rich soils. 
The pore system is obliquicaniculate or angusticaniculate (see Mikhailov et al. 1996), displaying a circular section (Figures 4(A), 6(A)). The pores have a mean diameter of 160mm (SD ^ 41) (N ¼ 37) measured in five sections from tangential surfaces with a total area of 142mm2. The average pore area is 0.021mm2 and the average density is 26 pores cm22. Pore distribution is uneven, making the relative pore area of about 0.55%. The measured eggshells show a mean radius of 57mm
(SD ^ 16) (N ¼ 27).

Discussion and comparison
The eggshells from Casal da Rola are similar in some respects to those from Paimogo (see Mateus et al. 1997; Antunes et al. 1998), a coeval locality eight kilometres north
of Casal da Rola that contains eggs and embryos. The Paimogo eggs (ML565) have been tentatively ascribed to the theropod L. antunesi (Mateus et al. 1998) based on
embryonic material (Mateus et al. 2012). The eggshells from Paimogo have a smooth external surface with an average shell thickness of 0.92mm. The eggshell microstructure
is distinctly prismatic, with narrow units with semi-round mammillae, accounting for 1/4 of total shell thickness. Diagenetically altered material dominates the external surface and fills the pores (Antunes et al. 1998). The pore system is obliquicaniculate or angusticaniculate, composed of simple and round pores with an average diameter of 180mm. Pore density varies from10 pores cm22 in the equatorial zone to 40 pores cm22 in the polar zones, with a pore relative area of 0.5%. The eggs are ellipsoidal to oval in shape, 130 £ 94mmin size,with an averageELof 1.4 based on complete eggs. Some of these anatomical features are also observed in the Casal da Rola specimens. Inparticular, both the Casal da Rola and Paimogo eggshells have similar thickness (0.87–0.92mm), external ornamentation (smooth), pore systems (obliquicaniculate or angusticaniculate), pore diameters (160–180 mm) and pore relative area (0.50–0.55%). Eggshells from both localities also share a similar microstructure with two distinct zones, a mammillary zone and a columnar zone. 

Despite that no partial or complete eggs were found, the size and shape of the Casal da Rola eggs were estimated using the mean radius of curvature of wellpreserved
eggshells. Making the mean radius of a prolate ellipsoid (r) equal to the measured mean radius (R ¼ 57 mm) and using the estimated EL( ¼ 1.4) from the Paimogo nest, we estimated an egg dimension of approximately 140 £ 100 mm, which is similar to the
dimensions obtained from the complete eggs. SD (^16mm) shows a range of curvatures, indicating that the eggs were oval rather than spherical in shape. 

If there were a mathematical correlation between any independent trait (e.g. SD) and the EL, and if the result for Casal da Rola is similar to 1.4 (Paimogo Index), then the
eggs from Casal da Rola would have been similar in size to those in the Paimogo nest.
Other nesting localities contain eggshells that are
comparable to the Casal da Rola material. Preprismatoolithus
coloradensis (Hirsch 1994), from the Upper
Jurassic Morrison Formation, is a basic obliquiprismatic
eggshell, with a thickness of 0.8–1.0 mm, although some eggs are slightly smaller in size, approximately 110 £ 60 mm. Prismatoolithus levis Zelenitsky and Hill, 1996, from the Oldman Formation in Alberta, Canada, and Two Medicine Formation in Montana (Upper Cretaceous), is also attributed to theropods (Zelenitsky et al. 1996; Varricchio et al. 2002). Prismatoolithus levis is similar to Preprismatoolithus coloradensis in terms of
eggshell thickness, but has different prismatic layer to mammillary layer thickness ratios, and an angusticaniculate pore system.

Assignment of the Casal da Rola eggshells to the oofamily Prismatoolithidae (Hirsch 1994) and oogenus Preprismatoolithus (Zelenitsky and Hill 1996) is based on
shared morphologic characteristics, including prismatic basic type, eggshell microstructure, pore system and eggshell thickness. Despite these similarities, there may be differences in the EL and estimated egg size.

Dinosauria Owen, 1842
Theropoda Marsh, 1881
Torvosaurus Galton and Jensen, 1979
Oofamily PHACELOOLITHIDAE Zeng and Zhang, 1979
(synonym of Dendroolithidae Zhao and Li, 1988)
Age and formation
Late Kimmeridgian, Lourinha˜ Formation, lower part of
Sobral Member.
Material and taphonomy
One isolated egg (ML1842) was highly deformed in a finegrained
sandstone block, and several corresponding
eggshell fragments (mostly taken from the egg). The
block was found at the base of a cliff, but was traced to the
original sandstone layer due to its lithological similarities.
Porto das Barcas (ML1842), Lourinha˜ area, Portugal. Not
to be confused with Porto das Barcas egg clutch ML1403
(Arau´jo et al. 2013).
The egg is flattened and broken into two parts. The
measured length and width are 23 cm and 15 cm
respectively (Figure 5(A)). The geometry and curvature
of the egg were not preserved, and plastic post-mortem
deformation prevents both accurate measurement of the
original shell curvature and reliable estimation of the egg
The inner surface of the preserved eggshell fragments
in tangential view is smooth with polygonal-shaped
mammillae and acicular internal structure radiating from
the nucleation centre towards the outer part (Figure 5(B)–
(D), (F)). The nucleation centres are spaced about 100–200 mm apart. In radial view (Figures 5(C), (D), 6(B)), wedge-shaped shell units, which broaden towards the outer surface and interconnect, display a distinct fanning pattern outwards to the edges of the shell units (Figures 5(C),(D), 6(B)). The mammillary layer in radial view seems to show a slight differentiation from the rest of the shell units. Growth lines are visible as arched lines (Figure 5(C)).
In tangential view, the outer surface is obscured by a coating of sand (Figure 5(E)) derived from the sandstone layer in which the fossil was embedded. Despite this sandy
coating, examination of tangential and radial sections under PLM reveals protruding ridges on the outer surface (Figures 5(E), 6(B)). Erosion was not measured. Both inner and outer surfaces display interconnected pores, forming an anastomosing system (Figure 5(E),(F)). The pore canals can also be seen to interconnect throughout the shell in radial view (Figures 5(C),(D), 6(B)). They are irregularly shaped and round to elongated in tangential view, with diameters ranging from 50 to 250 mm for more regular pores and 600 £ 100 mm for elongated pores.

Accordingly, the area of the pores is highly variable, averaging 0.019mm2 (SD ^ 0.014). The percentage of pore area to total surface area is estimated at 14%.
Discussion and comparisons Most features of the Porto das Barcas ML1842 eggshell
morphology, and the fact that there is no conspicuous columnar extinction pattern make assignment to spherulitic dinosauroid type most logical. Even though the
acicular crystallisation patterns in the mammillae are associated with turtle eggs (e.g. Fang et al. 2003), other characteristics of this eggshell point to a dinosauroid type.
The eggshells from Porto das Barcas are similar to
those from Portugal described by Kohring (1993) and
Arau´jo et al. (2012, 2013). The Porto das Barcas egg
clutch (ML1403) with the associated fossil embryos is the

most morphologically similar. Kohring (1993) mentions a spherulitic eggshell type with a thickness of 0.9–1.1mm and similar prolatocanaliculate pore system from the slightly older Porto Dinheiro locality, about 2 km south. An eggshell clutch (ML1403) found 600m south of the isolated egg preserves associated with neonate theropod embryos that have been assigned to Torvosaurus (Arau´jo et al. 2013). These eggs share the same range of eggshell thickness (0.9–1.2mm), ridged outer surface ornamentation, 
inner surface ornamentation with acicular crystallisation in the mammillae, wedge-shaped irregular shell units with distinct fanning pattern, prolatocanaliculate
pore system, irregular pore area and high porosity. 
The most similar eggshell type reported in the literature, besides the Portuguese findings, is the oogenus Dendroolithus Zhao and Li, 1988, from China that is placed into the oofamily Phaceloolithidae Zeng and Zhang, 1979 (synonym of Dendroolithidae Zhao and Li, 1988). 
The original diagnosis of Oogenus Dendroolithus Zhao and Li, 1988 after Zhao and Li (1988) and Fang et al. (2003) is as follows:
Eggs are small to medium size (6–20 cm), spherical to slightly oval. The eggshell has a dendrospherulitic morphotype, with shell units irregularly shaped. The shell units display a fanning pattern. The shell displays a prolatocanaliculate network throughout the eggshell. The outer surface ornamentation is irregular with crests and the
pores irregularly dispersed between the crests. Eggshell thickness is about 1.5 mm.
The Dendroolithus eggshell type is described as having narrow shell units which interlock towards the outer  surface, and an interconnecting prolatocanaliculate pore system (Zhao and Li 1988; Mikhailov et al. 1994; Zhao 1994). Therefore, this parataxon resembles more closely the morphology of ML 1842. Dendroolithus is known from Cretaceous deposits of China and Mongolia (Zhao and Li 1988; Mikhailov et al. 1994; Zhao 1994; Fang et al. 2003; Tanaka et al. 2012) and from the Late Jurassic of Portugal (Kohring 1993; Arau´jo et al. 2013), making this eggshell type more widespread than previously thought. Comparisons between the Late Cretaceous Mongolian and Chinese oospecies Dendroolithus are difficult because each has a different shell thickness range and external ornamentation. Dendroolithus wangdianensis Zhao and Li, 1988 has a shell thickness of 1.7–2.1 mm, whereas Dendroolithus verrucarius Mikhailov et al. 1994 has a shell thickness range of 1.8–3.8mm, with a second layer of spherulitic units. Dendroolithus microporosus Mikhailov et al. 1994 has a shell thickness of 2.0–2.7mm and comparatively small eggs (about 6 £ 7 cm) with smooth external ornamentation. Dendroolithus dendriticus Fang, Lu and Cheng, 1998 has a rugose outer surface and smooth inner surface, with a shell thickness of 1 mm. The shell units are wide and interconnect towards the outer surface. The mammillae are round with acicular crystallisation, and the pore canals are described as branching. Assignment of the Porto das Barcas (ML1842) material to the oofamily Phaceloolithidae is based on the following shared features: dendrospherulitic morphotype, rugose outer surface with crests and irregularly spaced pores, prolatocanaliculate pore system, interconnection towards the outer surface and irregular shape and fanning pattern of the shell units (Zhao and Li 1988; Mikhailov et al. 1994; Zhao 1994; Fang et al. 1998, 2003; Tanaka et al. 2012). Within Phaceloolithidae the oogenus Dendroolithus is the most similar to the Portuguese eggshells. However, some differences (mainly in fanning pattern with wider prisms and thinner eggshells in ML1842) are sufficient to warrant erection of a new oogenus. We have chosen not to assign a new oogenus because the embryonic remains in ML1403 allow definitive identification of the egg producer: the theropod Torvosaurus. The Dendroolithus egg type was initially assigned to either sauropods or ornithopods by Fang et al. (1998), Mikhailov et al. (1994) and Zhao (1994); but embryonic remains show that Dendroolithus and Phaceloolithidae were associated with therizinosaurs (Cohen et al. 1995; Mikhailov 1997; Tanaka et al. 2012). The Portuguese findings also strengthen the connection of Phaceloolithidae to theropods, particularly Torvosaurus and therizinosaurs Phylogenetic analysis There are few articles devoted to non-avian dinosaur eggshell cladistic analysis to support phylogenetic relationships among taxa, exist to provide a list of characters and data matrices: Varricchio and Jackson (2004), Grellet-Tinner and Makovicky (2006), Zelenitsky and Therrien (2008), Jin et al. (2010) and Tanaka et al. (2011, 2012). For eggshell-based cladistic analyses on other taxonomical groups: Aves see Lee et al. (1997), Grellet-Tinner (2006) and Zelenitsky and Modesto (2002) and for turtles see Winkler (2006). Varricchio and Jackson (2004) were pioneers in the theropod eggshell phylogeny. The eggs from Casal da Rola and Porto das Barcas were analysed (in Winclada, Nixon 1999) with the two most recent phylogenetic data matrixes (Jin et al. 2010; Tanaka et al. 2011). Using the following coding for Jin et al. (2010) data matrix: Casal da Rola (12002 110_1 ?0?20 0??0) and Porto das Barcas (13002 10011 ?0?30 1??0), the result Nelsen consensus tree was mostly resolved (Figure 7), in which the Porto das Barcas eggs (Torvosaurus) is a sister taxon of Dictyoolithus, and Casal da Rola is a sister taxon of Paimogo’s Lourinhanosaurus (length ¼ 53 steps; Ci: 55; Ri: 79). The character coding using the matrix provided by Tanaka et al. (2011) is as follows: Casal da Rola (31??? 00100 101013) and Porto das Barcas (100?? 00001 001001). The resulting Nelsen consensus tree (Ci: 62; Ri: 90; length: 43) with the data matrix of Tanaka et al. (2011) placed Porto das Barcas eggshell (Torvosaurus) in a polytomy with Dendroolithus and Faveoolithus and Casal da Rola in a trichotomy with Paimogo’s Lourinhanosaurus and Preprismatoolithus coloradensis. Paleobiological implications Prismatic eggs similar in morphotype and most likely attributable to basal theropods are now known from at least three different sites in Lourinha˜. The nesting preferences of basal theropods are virtually unknown due to the lack of fossil evidence. However, they may be inferred, in part, by the phylogenetic brackets, taphonomy and paleoenvironmental reconstructions. The eggshells from Casal da Rola and Paimogo are considered to be the same species or close taxonomic relatives (Antunes et al. 1998). Eggshells from both localities have a relative pore area higher than that of avian eggs of the same weight (Antunes et al. 1998; Deeming 2006). This suggests a need for maintenance of precise humidity and temperature conditions during incubation, possibly by covering the nest with soil or vegetation. The Casal da Rola and Paimogo sites share similar depositional settings: overbank deposits of mudstone and siltstone with carbonate nodules, which provide evidence of paleosol development due to seasonal moisture deficit. An extensive paleosol study from the Lourinha˜ Formation performed earlier by Myers et al. (2012) revealed paleoclimatic conditions for the Late Jurassic of Lourinha˜ with relatively high mean annual precipitation, temperatures and humidity compared to the present-day values (Myers et al. 2012). However, how the rainfall is distributed throughout the year will have a large impact on the environment, with possibly a pronounced arid season, thus confirming the taphonomic interpretation of the new egg sites from Lourinha˜. Conclusions We conclude that (i) the Casal da Rola eggshell is the same taxon as, or closely related to, the Paimogo eggshell (Lourinhanosaurus); (ii) the Casal da Rola, Porto das Barcas and Paimogo localities are preserved in coeval strata of uppermost Late Kimmeridgian age; (iii) the paleoenvironmental setting points to deposition of the eggs in distal alluvial plains in overbank sediments; (iv) the Porto das Barcas eggshells are of the oofamily Phaceloolithidae (close to the oogenus Dendroolithus) which represents the first Jurassic occurrence outside Asia and (v) the Porto das Barcas eggshells are attributable to Torvosaurus sp. Acknowledgements We would like to T.S. Myers (SMU) for the revision. We also thank Nuno Leal (FCT, UNL) for kindly assisting with SEM imaging. Many thanks also to Nury Lo´pez (Museu da Lourinha˜), Vero´nica Duarte (Museu da Lourinha˜), Joa˜o Russo (Museu da Lourinha˜, UNL) and Emanuel Tschopp (Museu da Lourinha˜, UNL) for energetic fieldwork. This research is part of Project Dinoeggs – dinosaur eggs and embryos in Portugal: paleobiological implications and paleoenvironmental settings (PTDC/BIA-EVF/113222/2009) funded by the Fundac¸a˜o para a Cieˆncia e Tecnologia (FCT), Portugal. 

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