Paleo News: January!

January was the first month of 2019, when the first of this year's paleontological discoveries were published!
In this first edition of Paleo News, I'll talk about my favorite fossils described in January.
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1-Bajadasaurus pronuspinax (Gallina et al, 2019)

(Credit: Gallina et al, 2019)

Bajadasaurus pronuspinax is a new species of dicreasaurid sauropod from the early Cretaceous Bajada Colorada Formation, Patagonia, Argentina. Several things make this sauropod remarkable. Firstly, some elements of the skull (dermal roof and palatal bones, a braincase, and a nearly complete lower jaw) were found, something quite rare in sauropods and thereby, expands the knowledge on the skull morphology of this group. Secondly, it is only the sixth species of dicrasaurid sauropod in the world! Thirdly, look at those spines!!! In the paper the authors claim the possibility those spines were used for defense, as they point forward. It is also said in the paper that "The temporal difference between Bajadasaurus and Amargasaurus, a 15 My younger spiny sauropod from the Neuquén basin, supports that the development of a fence of spines was likely adaptive over a long time period."
I'll now leave you with the abstract  (Here you can read the entire paper, as it is open access!)

Quoting from the abstract:
"Dicraeosaurids are a group of sauropod dinosaurs characterized by a distinctive vertebral column with paired, long, neural spines, present in an extreme fashion in the South American form Amargasaurus cazaui. This distinctive morphology has been interpreted as a support structure for a thermoregulatory sail, a padded crest for display, a dorsal hump acting as fat reservoir, and even as inner cores for dorsal horns. Other inferred functions (if any) of this structure were related to sexual display and/or defense strategies. Here we describe a new dicraeosaurid sauropod, Bajadasaurus pronuspinax gen. et sp. nov., from Patagonia which preserves the most complete skull of the group and has extremely elongate bifid cervical neural spines that point permanently forward, irrespective of the neck position. Although much shorter versions of this neural spine configuration were already recorded for other dicraeosaurid taxa, the long, anteriorly bent spines of this new dinosaur support the hypothesis that these elongate spines of dicraeosaurid sauropods served as passive defense structures."


2- Gobiraptor minutus (Lee et al, 2019)

(Credit: Lee et al, 2019)

Gobiraptor minus is a new species of oviraptorosaur from Mongolia, described from a juvenile specimen. It was found in the rocks of the late Cretaceous Negmet Formation. An interesting fact about Gobiraptor is the mandibular morphology, as it is unique among oviraptorids and likely to be linked to a specialized diet that probably included hard materials, such as seeds or bivalves.
Here you can read the original paper, which is open access!

Quoting from the abstract:
"Recent discoveries of new oviraptorosaurs revealed their high diversity from the Cretaceous Period in Asia and North America. Particularly, at the family level, oviraptorids are among the most diverse theropod dinosaurs in the Late Cretaceous of Mongolia and China. A new oviraptorid dinosaur Gobiraptor minutus gen. et sp. nov. from the Upper Cretaceous Nemegt Formation is described here based on a single holotype specimen that includes incomplete cranial and postcranial elements. The most prominent characters of Gobiraptor are its thickened rostrodorsal end of the mandibular symphysis and a rudimentary lingual shelf on each side of the dentary. Each lingual shelf is lined with small occlusal foramina and demarcated by a weakly developed lingual ridge. This mandibular morphology of Gobiraptor is unique among oviraptorids and likely to be linked to a specialized diet that probably included hard materials, such as seeds or bivalves. The osteohistology of the femur of the holotype specimen indicates that the individual was fairly young at the time of its death. Phylogenetic analysis recovers Gobiraptor as a derived oviraptorid close to three taxa from the Ganzhou region in southern China, but rather distantly related to other Nemegt oviraptorids which, as the results of recent studies, are also not closely related to each other. Gobiraptor increases diversity of oviraptorids in the Nemegt Formation and its presence confirms the successful adaptation of oviraptorids to a mesic environment."


3- Mnyamawamtuka moyowamkia (Gorsak & O'Connor, 2019)

(Credit: Gorsak & O'Connor, 2019)

 Mnyamawamtuka moyowamkia (try saying that  name 10 times fast!) is a new species of   titanosaurian sauropod from the middle  Cretaceous of Tanzania! This discovery is very  important, as "the Tanzania titanosaurians refine  perspectives on the development of African terrestrial faunas throughout the Cretaceous—a critical step in understanding non-marine paleobiogeographic patterns of Africa that have remained elusive until the past few years."
Here you can ckick to access the paper describing this beast!

Quoting from the abstract:
"The African terrestrial fossil record has been limited in its contribution to our understanding of both regional and global Cretaceous paleobiogeography, an interval of significant geologic and macroevolutionary change. A common component in Cretaceous African faunas, titanosaurian sauropods diversified into one of the most specious groups of dinosaurs worldwide. Here we describe the new titanosaurian Mnyamawamtuka moyowamkia gen. et sp. nov. from the Mtuka Member of the Galula Formation in southwest Tanzania. The new specimen preserves teeth, elements from all regions of the postcranial axial skeleton, parts of both appendicular girdles, and portions of both limbs including a complete metatarsus. Unique traits of M. moyowamkia include the lack of an interpostzygapophyseal lamina in posterior dorsal vertebrae, pronounced posterolateral expansion of middle caudal centra, and an unusually small sternal plate. Phylogenetic analyses consistently place M. moyowamkia as either a close relative to lithostrotian titanosaurians (e.g., parsimony, uncalibrated Bayesian analyses) or as a lithostrotian and sister taxon to Malawisaurus dixeyi from the nearby Aptian? Dinosaur Beds of Malawi (e.g., tip-dating Bayesian analyses). M. moyowamkia shares a few features with M. dixeyi, including semi-spatulate teeth and a median lamina between the neural canal and interpostzygapophyseal lamina in anterior dorsal vertebrae. Both comparative morphology and phylogenetic analyses support Mnyamawamtuka as a distinct and distant relative to Rukwatitan bisepultus and Shingopana songwensis from the younger Namba Member of the Galula Formation with these results largely congruent with newly constrained ages for the Mtuka Member (Aptian–Cenomanian) and Namba Member (Campanian). Coupled with recent discoveries from the Dahkla Oasis, Egypt (e.g., Mansourasaurus shahinae) and other parts of continental Afro-Arabia, the Tanzania titanosaurians refine perspectives on the development of African terrestrial faunas throughout the Cretaceous—a critical step in understanding non-marine paleobiogeographic patterns of Africa that have remained elusive until the past few years."