n/a

n/a

n/a

n/a

n/a

Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs, short necks, and are generally considered to be low browsers. A new stegosaur, Miragaia longicollum gen. et sp. nov., from the Late Jurassic of Portugal, has a neck comprising at least 17 cervical vertebrae. This is eight additional cervical vertebrae when compared with the ancestral condition seen in basal ornithischians such as Scutellosaurus.
Miragaia has a higher cervical count than most of the iconically long-necked sauropod dinosaurs. Long neck length has been achieved by ‘cervicalization’ of anterior dorsal vertebrae and probable lengthening of centra. All these anatomical features are evolutionarily convergent with those exhibited in the necks of
sauropod dinosaurs. Miragaia longicollum is based upon a partial articulated skeleton, and includes the only known cranial remains from any European stegosaur. A well-resolved phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus; this new topology challenges the common view of Dacentrurus as a basal stegosaur.

n/a

A new Late Cretaceous turtle, Angolachelys mbaxi gen. et sp. nov., from the Turonian (90 Mya) of Angola, represents the oldest eucryptodire from Africa. Phylogenetic analysis recovers Angolachelys mbaxi as the sister taxon of Sandownia harrisi from the Aptian of Isle of Wight, England. An unnamed turtle from the Albian Glen Rose Formation of Texas (USA) and the Kimmeridgian turtle Solnhofia parsonsi (Germany), are successively more distant sister taxa. Bootstrap analysis suggests those four taxa together form a previously unrecognized monophyletic clade of marine turtles, herein named Angolachelonia clade nov., supported by the following synapomorphies: mandibular articulation of quadrate aligned with or posterior to the occiput, and basisphenoid not visible or visibility greatly reduced in ventral view. Basal eucryptodires and angolachelonians originated in the northern hemisphere, thus Angolachelys represents one of the first marine amniote lineages to have invaded the South Atlantic after separation of Africa and South America.

General vertebrate paleontological techniques that have been used in the Museum of Lourinhã (Portugal) are presented here, in particular those applied to a stegosaurian dinosaur skeleton, Miragaia longicollum. A monolith jacket technique using polyurethane foam and plaster is presented. Mechanical preparation
techniques combining the use of an electric grinder and airscribes proved effective during the initial phases of preparation on well-preserved bone embedded in hard matrix. We also present a technique to mould monoliths in the early stages of preparation, creating a thin silicone rubber mould in several contiguous
parts. To mould and cast monoliths before removing individual bones has proven valuable for the preservation of taphonomic data and for display purposes. Polyurethane resin combined with plaster is useful for small casts, while polyester resin applied in four layers is the preferred technique for larger casts.
The four layers are composed of: a first thin layer of polyester resin with bone colour; followed by another layer of polyester resin of sediment colour and containing glass microspheres to make it thicker. The third layer is composed of fibre glass chopped strands, and the fourth is composed of fibre glass mats embedded
in plain polyester resin. 3D scanning and digitization techniques where tested for the storage of osteological information of individual bones and proved very promising.

A partial sauropod was found in 1996 in Vale Pombas, north of Lourinhã, Central West of Portugal, in the Lourinhã Formation, top of Amoreira Porto Novo member dated as c. 150 M.a. (Early Tithonian, Late Jurassic) and is currently housed at Museum of Lourinhã, in Portugal. The specimen (ML368) comprises a complete tooth with root, anterior chevron and almost complete right forelimb including partial scapula, complete coracoid, humerus, ulna, radius, metacarpals I, III and V, phalanx, and ungual phalanx I. It can be ascribed to Turiasaurus riodevensis, which was previously described from the Villar del Arzobispo
Formation at Riodeva (Teruel, Spain). Characters shared with T. riodevensis holotype include: curvature and asymmetry of tooth crown, expansion of crown, outline of humerus, medial deflection of the proximal end of humerus, shape and prominence of deltopectoral crest, vertical ridge in the distal half of the ulna (considered as diagnostic of Turiasauria), configuration of metacarpals, and bone proportions. It differs from T. riodevensis holotype by the smaller size and the more rectangular ungual phalanx in lateral view. The sediments from which the Riodeva specimen was recovered were previsouly thought to be Tithonian to Berriasian in age. The presence of this species in Portugal, in beds confidently dated as Early
Tithonian, may allow a more precise date for the Riodeva type locality of early Tithonian in age. The humerus of the Portuguese T. riodevensis is 152 cm long. Although shorter than the Spanish specimen (790 mm), it represents a large individual. All adult sauropods recovered in Portugal thus far are very large individuals: Dinheirosaurus (estimated body length is 20-25 m), Lusotitan (humerus length estimated to be 205 cm), Lourinhasaurus (femur length: 174 cm), and Turiasaurus here reported. The lack of of small or medium adult body-size sauropods in the Late Jurassic of Portugal, suggests browsing niches thought to be occupied by smaller forms, could be have been available for other dinosaurs, like the long necked stegosaur Miragaia longicollum.