Introducing Isaberrysaura

Isaberrysaura skull in lateral view and maxillary teeth (Adapted from Salgado et al., 2017)

Isaberrysaura mollensis gen. et sp. nov. is the first dinosaur recovered in the marine-deltaic deposits of the Los Molles Formation (Neuquén Province, Argentina), and the first neornithischian dinosaur known from the Jurassic of South America. So far, the South American record of Jurassic ornithischian dinosaurs was limited to a few specimens belonging to Heterodontosauriformes, a clade of small-sized forms that survived in Europe up to the Early Cretaceous. The name Isaberrysaura is derived from “Isa Berry” (Isabel Valdivia Berry, who reported the initial finding) and the Greek word “saura” (lizard).

The holotype of Isaberrysaura is an incomplete articulated skeleton with an almost complete skull, and a partial postcranium consisting of 6 cervical vertebrae, 15 dorsal vertebrae, a sacrum with a partial ilium and an apparently complete pubis, 9 caudal vertebrae, part of a scapula, ribs, and unidentifiable fragments. One of the most notable features of the discovery is the presence of permineralized seeds in the middle-posterior part of the thoracic cavity. The seeds were assigned to the Cycadales (Zamiineae) on the basis of a well-defined coronula in the micropylar region. The findings suggest the hypothesis of interactions (endozoochory) between cycads and dinosaurs, especially in the dispersion of seeds.

Gut content of Isaberrysaura mollensis gen. et sp. nov. (a–c), seeds of cycads (c), and other seeds (s); rib (r). From Salgado et al., 2017

The cranium of Isaberrysaura is reminiscent of that of the thyreophorans. The skull is estimated to be 52 cm long and 20 cm wide across the orbits. The jugal is triradiate and the nasals are ~20 cm long. There are two supraorbital bones; one is elongated (~10 cm), as in stegosaurs, and the other element interpreted as a posterior supraorbital is located on the posterior margin of the orbit. It has at least six premaxillary teeth, and there is no diastema between the premaxillary and the maxillary tooth row. Despite the many similarities between Isaberrysaura and the thyreophorans, the phylogenetic analysis indicates that Isaberrysaura is a basal ornithopod, suggesting that both Thyreophora and neornithischians could have achieved significant convergent features.


Salgado, L. et al. A new primitive Neornithischian dinosaur from the Jurassic of Patagonia with gut contents. Sci. Rep. 7, 42778; doi: 10.1038/srep42778 (2017)

Wenupteryx uzi, a Jurassic pterosaur from Patagonia.

Wenupteryx uzi, photograph of the slab. From Codorniu-Gasparini 2013.

Wenupteryx uzi, photograph of the slab. From Codorniu-Gasparini 2013.

By the Mid-Jurassic, Gondwana, the southern margen of supercontinent Pangea started to break up in different blocks: Antarctica, Madagascar, India, and Australia in the east, and Africa and South America in the west. During this period pterosaurs had a worldwide distribution, but their known record is markedly biased toward the northern hemisphere. For example, the ‘Solnhofen Limestone’ beds in Germany yielded important pterosaur specimens, mostly members of the genera Pterodactylusand Rhamphorhynchus. Other famous fossil-bearing deposits are from North America, and from the Tiaojishan Formation in China.

In contrast, the fossil remains of pterosaurs from Jurassic sediments are very scarce in the southern hemisphere. The oldest record comes from the Middle Jurassic of Patagonia, in the Cañadon Asfalto Formation, which is mainly composed of lacustrine deposits.

Wenupteryx uzi, reconstruction from Codorniú 2013.

Wenupteryx uzi, reconstruction from Codorniú 2013.

The most complete pterosaur known so far is Wenupteryx uzi described by Laura Codorniu and Zulma Gasparini. In the Mapuche Languaje, Wenu means “sky” and uzi means “fast”.

Wenupteryx uzi, is a small pterosaur . The bones recovered so far are a nearly complete post-cranial skeleton,which includes: some cervical and dorsal vertebrae; a few thoracic ribs, a proximal right-wing (humerus, ulna and radius, right metacarpal IV, pteroid), a more complete left-wing and hindlimb bones. This pterosaurs has a wingspan approaching 1-10 m.
Based on the presence of some characters, like the depressed neural arch of the mid-series cervicals, with a low neural spine and elongate mid-series cervicals. Wenupteryx uzi is closely related to the Euctenochasmatia, which matches with Unwin’s phylogeny (Unwin, 2003).


Laura Codorniú and Zulma Gasparini (2013). «The Late Jurassic pterosaurs from northern Patagonia, Argentina». Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103 (3–4):  pp. 399–408. doi:10.1017/S1755691013000388.

Brief paleontological history of planktonic foraminifera.


Neogloboquadrina dutertrei. (Credit: Dr Kate Darling).

Planktonic foraminifera made their first appearance in the Late Triassic. Although, identifying the first occurrence of planktonic foraminifera is complex, with many suggested planktonic forms later being reinterpreted as benthic. They are present in different types of marine sediments, such as carbonates or limestones, and are excellent biostratigraphic markers.

Their test are made of  globular chambers composed of secrete calcite or aragonite, with no internal structures and  different patterns of chamber disposition: trochospiral, involute trochospiral and planispiral growth. During the Cenozoic, some forms exhibited supplementary apertures or areal apertures. The tests also show perforations and a variety of surface ornamentations like cones, short ridges or spines.

The phylogenetic evolution of planktonic foraminifera are closely associated with global and regional changes in climate and oceanography.

planktonic foraminifera evolution

The evolution of early planktonic foraminifera (From Boudagher-Fadel, 2013)

All species of Late Triassic and Jurassic planktonic foraminifera are members of the superfamily Favuselloidea. They present a test composed by aragonite, with microperforations, and sub-globular adult chambers. After the major End Triassic event, the Jurassic period saw warm tropical greenhouse conditions worldwide. The surviving planktonic foraminifera were usually dominated by small globular forms.

It was suggested  that a second transition from a benthic to a planktonic mode of life took place at the Jurassic, which occurred under conditions similar to those that triggered planktonic speciation in the Late Triassic (hot and dry global climate, and low sea levels).

During the Cretaceous,  the favusellids must have made the transition from being aragonitic to calcitic.  Also, in the Late Aptian there was a significant number of planktonic foraminiferal extinctions, but these were compensated by the establishment of a large number of new genera at the Aptian–Albian boundary.

Planktonic foraminifera from the Sargasso Sea in the North Atlantic Ocean. (Photograph courtesy Colomban de Vargas, EPPO/SBRoscoff.)

Planktonic foraminifera from the Sargasso Sea in the North Atlantic Ocean. (Photograph courtesy Colomban de Vargas, EPPO/SBRoscoff.)

The Paleogene assemblage of planktonic foraminifera was derived from the few species that survive the mass extinction event at the end of the Cretaceous.

In the Early Miocene, the planktonic foraminifera were most abundant and diverse in the tropics and subtropics, and after the Mid-Miocene Climatic Optimum, many species were adapted to populate temperate and sub-polar oceans.

During the Middle and Late Pliocene, the final closure of the Central American seaway, changed oceanic circulation and drove a significant number of species extinctions. Most modern, living species originated in the Pliocene and Pleistocene.


Armstrong, H. A., Brasier, M. D., 2005. Microfossils (2nd Ed). Blackwell, Oxford.

Boudagher-Fadel, MK; (2013) Biostratigraphic and Geological Significance of Planktonic Foraminifera. (2nd ed.)