[Paleontology • 2019] Exquisitely-preserved, High-definition Skin Traces in Diminutive Theropod Tracks from the Cretaceous of Korea

in Kim, Lockley, Lim & Xing, 2019. 

DOI: 10.1038/s41598-019-38633-4

(Illustration by Zifeng Wang.) 

Abstract

Small theropod tracks, ichnogenus Minisauripus, from the Jinju Formation (Cretaceous) of Korea reveal exquisitely preserved skin texture impressions. This is the first report for any dinosaur of skin traces that cover entire footprints, and every footprint in a trackway. Special sedimentological conditions allowed footprint registration without smearing of skin texture patterns which consist of densely-packed, reticulate arrays of small (<0.5 mm) polygons, preserved as both impressions and casts, the latter essentially foot replicas. The skin texture resembles that reported for two Lower Cretaceous avian theropods (birds) from China which had quite different foot morphologies. This is also the oldest report of Minisauripus from Korea predating five reports from the Haman Formation of inferred Albian age. Minisauripus is now known from six Korean and three Chinese localities, all from the Lower Cretaceous. This gives a total sample of ~95 tracks representing ~54 trackways. With >80% of tracks <3.0 cm long, Minisauripus is pivotal in debates over whether small tracks represent small species, as the database suggests, or juveniles of large species.

(Illustration by Zifeng Wang.) 

Kyung Soo Kim, Martin G. Lockley, Jong Deock Lim and Lida Xing. 2019. Exquisitely-preserved, High-definition Skin Traces in Diminutive Theropod Tracks from the Cretaceous of Korea. Scientific Reports. volume 9, Article number: 2039.  DOI: 10.1038/s41598-019-38633-4

Tiny dinosaur left ‘perfect footprint’ in the rain by @aurevig link.medium.com/vCxTGLgVLV

Perfectly preserved dinosaur skin found in Korea phys.org/news/2019-04-perfectly-dinosaur-skin-korea.html via @physorg_com

 facebook.com/218228675013635/photos/1221367508033075

    

[Paleontology • 2019] Nhandumirim waldsangae • A New Dinosaur with Theropod Affinities from the Late Triassic Santa Maria Formation, South Brazil

Nhandumirim waldsangae 

Marsola, Bittencourt, Butler, Da Rosa, Sayão & Langer, 2019

  DOI: 10.1080/02724634.2018.1531878 

 jornal.usp.br/ciencias

ABSTRACT

The Late Triassic (Carnian) upper Santa Maria Formation of south Brazil has yielded some of the oldest unequivocal records of dinosaurs. Here, we describe a new saurischian dinosaur from this formation, Nhandumirim waldsangae, gen. et sp. nov., based on a semiarticulated skeleton, including trunk, sacral, and caudal vertebrae, one chevron, right ilium, femur, partial tibia, fibula, and metatarsals II and IV, as well as ungual and non-ungual phalanges. The new taxon differs from all other Carnian dinosauromorphs through a unique combination of characters, some of which are autapomorphic: caudal centra with sharp longitudinal ventral keels; brevis fossa extending for less than three-quarters of the ventral surface of the postacetabular ala of the ilium; dorsolateral trochanter ending well distal to the level of the femoral head; distal part of the tibia with a mediolaterally extending tuberosity on its cranial surface and a tabular caudolateral flange; conspicuous, craniomedially oriented semicircular articular facet on the distal fibula; and a straight metatarsal IV. This clearly distinguishes Nhandumirim waldsangae from both Saturnalia tupiniquim and Staurikosaurus pricei, which were collected nearby and at a similar stratigraphic level. Despite not being fully grown, the differences between Nhandumirim waldsangae and those saurischians cannot be attributed to ontogeny. The phylogenetic position of Nhandumirim waldsangae suggests that it represents one of the earliest members of Theropoda. Nhandumirim waldsangae shows that some typical theropod characters were already present early in dinosaur evolution, and it represents possibly the oldest record of the group known in Brazil.

  Silhouette depicting the preserved bones of Nhandumirim waldsangae, gen. et sp. nov. (LPRP/USP 0651).

SYSTEMATIC PALEONTOLOGY 

DINOSAURIFORMES Novas, 1992, sensu Nesbitt, 2011 

DINOSAURIA Owen, 1842, sensu Padian and May, 1993 

SAURISCHIA Seeley, 1887, sensu Gauthier, 1986 

cf. THEROPODA Marsh, 1881, sensu Gauthier, 1986 

NHANDUMIRIM WALDSANGAE, gen. et sp. nov

Etymology— The generic name combines the Portuguese derivatives of the indigenous Tupi-Guarani words ‘Nhandu’ (running bird, common rhea) and ‘Mirim’ (small), in reference to the size and inferred cursorial habits of the new dinosaur. The specific epithet name refers to the Waldsanga site, the historic outcrop (Langer, 2005a) that yielded this new species.

Júlio C. A. Marsola, Jonathas S. Bittencourt, Richard J. Butler, Átila A. S. Da Rosa, Juliana M. Sayão and Max C. Langer. 2019. A New Dinosaur with Theropod Affinities from the Late Triassic Santa Maria Formation, South Brazil. Journal of Vertebrate Paleontology. e1531878 DOI: 10.1080/02724634.2018.1531878   

Parente do tiranossauro viveu no Brasil há 233 milhões de anos jornal.usp.br/ciencias/ciencias-biologicas/parente-do-tiranossauro-viveu-no-brasil-ha-233-milhoes-de-anos via @usponline 

[Paleontology • 2019] Gobiraptor minutus • A New Baby Oviraptorid Dinosaur (Dinosauria: Theropoda) from the Upper Cretaceous Nemegt Formation of Mongolia

Gobiraptor minutus 

Lee, Lee, Chinsamy, Lü, Barsbold & Tsogtbaatar, 2019

 DOI: 10.1371/journal.pone.0210867

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.

Fig 4. Postcranial elements of the holotype specimen (MPC-D 102/111) of Gobiraptor minutus gen. et sp. nov.
 (A) Skeletal reconstruction in left lateral view (missing and damaged portions of the bones in gray). (B) Left ilium in lateral view. (C) Proximal caudal vertebrae in left lateral view with close-up of the infraprezygapophyses. (D) Chevron in cranial view. (E-F) Right scapula in dorsal (E) and lateral (F) views. (G) Last sacral and the two proximalmost caudals in left lateral view. (H) Right pubis in medial view. (I) Right ischium in lateral view. (J) Right femur in distal view. (K) Left metatarsus and distal tarsals in proximal view. (L) Right femur in cranial view. (M-N) Left metatarsus in lateral (M) and dorsal (N) views. 

Abbreviations: acr, acromion process; ant, antitrochanter; ch, chevron; cv, caudal vertebra(e); diprf, dorsal infraprezygapophyseal fossa; dt, distal tarsal(s); fct, cranial trochanter of femur; fh, femoral head; gl, glenoid fossa; idf, infradiapophyseal fossa; lc, lateral condyle; mc, medial condyle; mep, medial epicondyle; miprf, middle infraprezygapophyseal fossa; mt II, metatarsal II; mt IV, metatarsal IV; mt V, metatarsal V; ns, neural spine; obp, obturator process; pra, preacetabular process; pup, pubic peduncle; sprf, supraprezygapophyseal fossa; sv, sacral vertebra; tfc, tibiofibular crest; tp, transverse process; viprf, ventral infraprezygapophyseal fossa. Scale bars equal 10 cm in (A); 1 cm in (B-N).

Systematic paleontology

Dinosauria Owen, 1842

Theropoda Marsh, 1881

Maniraptora Gauthier, 1986

Oviraptorosauria Barsbold, 1976

Oviraptoridae Barsbold, 1976

Gobiraptor minutus gen. et sp. nov.

Etymology: The generic name Gobiraptor is a combination of ‘Gobi’ which refers to the Gobi Desert where the holotype specimen was found and ‘raptor’ which is Latin for thief. The specific name ‘minutus’ is Latin for small and refers to the small size of the holotype specimen.

Holotype: The holotype specimen (MPC-D 102/111) (Figs 2–4, S2 and S3 Figs) consists of mostly incomplete cranial and postcranial elements including ventral parts of the premaxillae and maxillae, a tip of the right jugal, fused vomer, parts of articulated pterygoids and ectopterygoids, incomplete right palatine, central part of the left postorbital, partial right quadrate and quadratojugal, incomplete lower jaw, with most of its elements broken, the last sacral vertebra which is articulated with the two proximalmost caudal vertebrae, articulated but incomplete proximal caudal vertebrae, fragments of chevrons, partial right scapula and humerus, incomplete pelvic girdles, nearly complete both femora, complete left metatarsus with distal tarsals 3 and 4, incomplete left pedal digits I, III, and IV, and several unidentified fragments. MPC-D 102/111 was also found with other theropod skeletons including postcranial elements of alvarezsaurids and larger oviraptorids.

Type locality and horizon: Altan Uul III, Ömnögovi Province, Mongolia (Fig 1, S1 Fig). Upper Cretaceous Nemegt Formation.

Diagnosis: Gobiraptor minutus is an oviraptorid dinosaur diagnosed by the following unique set of characteristics (autapomorphies are marked with an asterisk): a flat articular surface for the quadratojugal on the quadrate*; rostrocaudally elongate dentary rostral to the external mandibular fenestra; extremely thickened rostrodorsal end of the mandibular symphysis with a caudal expansion of its dorsal surface *; a rudimentary lingual triturating shelf on each dentary bearing small occlusal foramina*; a weakly developed lingual ridge on each lingual shelf*; absence of any prominent symphyseal ventral process of the dentary; coronoid bone present; the rostral end of the coronoid bone wedging into the ventral surface of the dorsal ramus of the dentary*; cranial trochanter of the femur separated from the greater trochanter with a distinct furrow between them.

....

   

Conclusions: 

Gobiraptor minutus gen. et sp. nov. is a new derived oviraptorid represented by an incomplete skeleton including both cranial and postcranial elements. Gobiraptor is primarily distinguished from other oviraptorids by its dentary with the extremely thickened rostrodorsal end of the mandibular symphysis, lingual ridges and lingual shelves bearing occlusal foramina. The unique morphology of the mandible of Gobiraptor is probably closely related to a crushing-related feeding style and a specialized diet, which may have incorporated hard seeds or shelled organisms. Although Gobiraptor was recovered from the Nemegt Formation, its phylogenetic position showed a close relationship with three Ganzhou oviraptorids. The distant relationships among the Nemegt oviraptorids on the phylogenetic tree were reaffirmed in this study. Therefore, it is highly unlikely that the evolution of these unusually diverse animals was facilitated by a simple sympatric speciation. The presence of Gobiraptor in the Nemegt Formation, together with occurrences of other oviraptorids, also indicates that abundant oviraptorids lived in mesic environments and they were one of the most diverse and successful groups of dinosaurs in the Nemegt region.

      

 Sungjin Lee, Yuong-Nam Lee , Anusuya Chinsamy, Junchang Lü†, Rinchen Barsbold and Khishigjav Tsogtbaatar. 2019. A New Baby Oviraptorid Dinosaur (Dinosauria: Theropoda) from the Upper Cretaceous Nemegt Formation of Mongolia.  PLoS ONE. 14(2): e0210867. DOI: 10.1371/journal.pone.0210867

New oviraptorosaur species discovered in Mongolia phys.org/news/2019-02-oviraptorosaur-species-mongolia.html via @physorg_com

     

[Paleontology • 2018] Saltriovenator zanellai • The Oldest Ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, Sheds Light on the Evolution of the Three-fingered Hand of Birds

Saltriovenator zanellai 

Dal Sasso​, Maganuco & Cau, 2018

    DOI: 10.7717/peerj.5976 

Abstract 

The homology of the tridactyl hand of birds is a still debated subject, with both paleontological and developmental evidence used in support of alternative identity patterns in the avian fingers. With its simplified phalangeal morphology, the Late Jurassic ceratosaurian Limusaurus has been argued to support a II–III–IV digital identity in birds and a complex pattern of homeotic transformations in three-fingered (tetanuran) theropods. We report a new large-bodied theropod, Saltriovenator zanellai gen. et sp. nov., based on a partial skeleton from the marine Saltrio Formation (Sinemurian, lowermost Jurassic) of Lombardy (Northern Italy). Taphonomical analyses show bone bioerosion by marine invertebrates (first record for dinosaurian remains) and suggest a complex history for the carcass before being deposited on a well-oxygenated and well-illuminated sea bottom. Saltriovenator shows a mosaic of features seen in four-fingered theropods and in basal tetanurans. Phylogenetic analysis supports sister taxon relationships between the new Italian theropod and the younger Early Jurassic Berberosaurus from Morocco, in a lineage which is the basalmost of Ceratosauria. Compared to the atrophied hand of later members of Ceratosauria, Saltriovenator demonstrates that a fully functional hand, well-adapted for struggling and grasping, was primitively present in ceratosaurians. Ancestral state reconstruction along the avian stem supports 2-3-4-1-X and 2-3-4-0-X as the manual phalangeal formulae at the roots of Ceratosauria and Tetanurae, confirming the I–II–III pattern in the homology of the avian fingers. Accordingly, the peculiar hand of Limusaurus represents a derived condition restricted to late-diverging ceratosaurians and cannot help in elucidating the origin of the three-fingered condition of tetanurans. The evolution of the tridactyl hand of birds is explained by step-wise lateral simplification among non-tetanuran theropod dinosaurs, followed by a single primary axis shift from digit position 4 to 3 at the root of Tetanurae once the fourth finger was completely lost, which allowed independent losses of the vestigial fourth metacarpal among allosaurians, tyrannosauroids, and maniraptoromorphs. With an estimated body length of 7.5 m, Saltriovenator is the largest and most robust theropod from the Early Jurassic, pre-dating the occurrence in theropods of a body mass approaching 1,000 Kg by over 25 My. The radiation of larger and relatively stockier averostran theropods earlier than previously known may represent one of the factors that ignited the trend toward gigantism in Early Jurassic sauropods.

Figure 1: Fossil location and geological setting. (A–C) Outline maps of Italy, Lombardy, Varese Province, and Saltrio Municipality; (D) satellite view of the Saltrio area, with map marker indicating the Saltrio quarry; (E) map marker indicating the stratigraphic log in the Saltrio quarry; (F) the ammonite Paracoroniceras cf. gmuendense and (G) the nautiloid Cenoceras striatum, both found associated in the layer containing the dinosaur bones; (H) glauconite present as accessory mineral in block C (counterpart of block A of Fig. 2); (I) the discordance between the Dolomia Principale Fm. and the Saltrio Fm.; (J) thin sections of the layer embedding the dinosaur bones; (K) stratigraphic log of the Saltrio quarry, based on Croce (2005), with geological time scale and ammonites zones based on Sacchi Vialli (1964) and Ogg & Hinnov (2012). Abbreviations: c, crinoids; f, foraminifers; g, gastropods; o, ostracods. Scale bars equal 200 km in (A), 30 km in (B), six km in (C), one km in (D), one mm in (K), and 150 cm in (L). Photos by F. Berra, G. Bindellini, M. Croce, and G. Pasini; drawings by M. Croce and S. Maganuco.

Figure 1: Fossil location and geological setting.
(A–C) Outline maps of Italy, Lombardy, Varese Province, and Saltrio Municipality.

Scale bars equal 200 km in (A), 30 km in (B), six km in (C).

Figure 1: Fossil location and geological setting.
 (D) satellite view of the Saltrio area, with map marker indicating the Saltrio quarry; (E) map marker indicating the stratigraphic log in the Saltrio quarry; (F) the ammonite Paracoroniceras cf. gmuendense and (G) the nautiloid Cenoceras striatum, both found associated in the layer containing the dinosaur bones; (H) glauconite present as accessory mineral in block C (counterpart of block A of Fig. 2); (I) the discordance between the Dolomia Principale Fm. and the Saltrio Fm.; (J) thin sections of the layer embedding the dinosaur bones; (K) stratigraphic log of the Saltrio quarry, based on Croce (2005), with geological time scale and ammonites zones based on Sacchi Vialli (1964) and Ogg & Hinnov (2012). Abbreviations: c, crinoids; f, foraminifers; g, gastropods; o, ostracods.

Scale bars equal one mm in (K), and 150 cm in (L). Photos by F. Berra, G. Bindellini, M. Croce, and G. Pasini; drawings by M. Croce and S. Maganuco.

Figure 2: Taphonomy of the Saltrio theropod (block A). Bones of Saltriovenator mapped in temporal sequence (A–C), gradually emerging from the embedding rock during acid preparation of block A. Numbers refer to each fragment, not to a specific anatomical position. The latter is reported in other figures, for fragments that were later reconnected into more complete bones. Abbreviations as in text, and as follows: ind, indeterminate bone; ir, indeterminate rib; l (left) and r (right) are specified for fragments of paired bones certainly (appendicular elements) or tentatively (ribs) positioned in the skeleton. Macroborings facing front, side and back are mapped respectively with yellow circles, semicircles, and hatched circles. Scale bars equal 10 cm. Photos by G. Bindellini and C. Dal Sasso.

Figure 4: Selected elements used in the diagnosis of Saltriovenator zanellai n. gen. n. sp. Right humerus in medial (A), frontal (B) and distal (C) views; (D) left scapula, medial view; (E) right scapular glenoid and coracoid, lateral view; (F) furcula, ventral view; tooth, labial (G) and apical (H) views; (I) left humerus, medial view; right second metacarpal in dorsal (J), lateral (L) and distal (N) views; first phalanx of the right second digit in dorsal (K), lateral (M) and proximal (O) views; (P–T) right third digit in proximal, dorsal and lateral views; (U) right distal tarsal IV, proximal view; third right metatarsal in proximal (V) and frontal (X) views; second right metatarsal, proximal (W) and frontal (Y) views; (Z) reconstructed skeleton showing identified elements (red).

Abbreviations as in text, asterisks mark autapomorphic traits. 

Scale bars: 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G). 

Photos by G. Bindellini, C. Dal Sasso and M. Zilioli; drawing by M. Auditore.

Figure 5: Cranio-mandibular fragments, tooth, and ribs of Saltriovenator zanellai. Indeterminate cranial fragment (A–B); right splenial in lateral (C), rostral (D) and ventral (E) views; right prearticular in lateral (F) and rostral views (G); sketch of the right prearticular of MOR 693 (Allosaurus fragilis) with virtual cross-section (H) diagnostic for G, also confirmed by CT slicing of the left side element of MOR 693 (I); splenial and prearticular in medial view, positioned in a reconstructed right lower jawof Saltriovenator (J). Maxillary or dentary tooth in labial (K) and apical (L) views; close-up of the distal carina and denticles in lingual (M) and distal (N) views. Left cervical rib (O) in craniolateral view; fragmentary right (P) and left (Q) dorsal ribs in craniolateral view.

Abbreviations as in text, ribs labeled as in Fig. 2 maps and caption. Scale bars equal two cm in (A)–(I), five cm in (J), one cm in (K), five mm in (L), one mm in (M)–(N), five cm in (O)–(Q). 

Photos by G. Bindellini, C. Dal Sasso, and M. Zilioli; drawing by C. Dal Sasso.

Systematic Paleontology

DINOSAURIA Owen, 1842

THEROPODA Marsh, 1881

NEOTHEROPODA Bakker, 1986

CERATOSAURIA Marsh, 1884

Saltriovenator zanellai gen. et sp. nov.

Etymology. Saltrio, Italian toponym name, from the locality where the holotype was found; venator, Latin word for hunter, it also refers to a type of Roman gladiator; zanellai, Latin genitive dedicated to Angelo Zanella, who discovered the fossil.

Holotype. MSNM V3664, very fragmentary and disarticulated skeleton (Figs. 4–13), represented by the following elements (among brackets, number of fragments per bone): partial right splenial (2) and right prearticular (1); cervical (1) and dorsal (9) ribs; furcula (1), incomplete left scapula (16), right scapular glenoid (1), partial right coracoid (5), fragmentary right sternal plate (2); right humerus (2), and proximal half of left humerus (2); ?right ?distal carpal, right metacarpal II, right phalanx II-1, fragmentary right phalanx II-2, and tip of the ?second right ungual phalanx; complete third right manual digit (phalanges III-1 to III-4); right distal tarsals III and IV, proximal portions of right metatarsals II, III, IV, and V(2).

Referred material. MSNM V3659, one maxillary or dentary tooth (Figs. 4 and 5).

Comments. As noted above, the discovery of all skeletal elements at the same time in a very restricted spot, the fact that all of them are of matching size, and that fragmentary and anatomically adjacent elements are of matching morphology, leave no doubt that all bones referred to the holotype come from the same individual. We prudentially exclude from the holotype the single tooth, which was found relatively associated to the bones but lacking its root and any jaw bone connection, thus raising the doubt that it might represent a shed tooth.

Type locality. “Salnova” quarry, Saltrio, Varese Province, Lombardy (northern Italy).

Horizon and Age. Saltrio Fm. (sensu Gnaccolini, 1964), bucklandi Zone, early Sinemurian (199.3–197.5 mya) (Ogg & Hinnov, 2012).

Diagnosis. Mid-to-large sized ceratosaurian characterized by the following unique combination of anatomical features (autapomorphies marked by asterisk—see also Fig. 4): humerus with deltopectoral crest protruding craniomedially for more than twice the shaft diameter, with distal lamina forming an abrupt corner (about 90°) with the proximodistal axis of the humeral shaft; metacarpal II with hypertrofied semicircular extensor lip protruding over the condylar level* and bordering dorsolaterally a very deep and wide extensor pit; phalanx II-1 with flexor palmar groove which is deep and narrow*, and bearing a distinct bump distal to the dorsal extensor process*; manual ungual III with prominent flexor tubercle which is distinctly separated from articular facet by a concave cleft.

 .....

Simplified evolutionary tree of predatory dinosaurs (theropods). Saltriovenator predates the massive meat-eating dinosaurs by over 25 million years: it is the oldest known ceratosaurian, and the world's largest predatory dinosaur from the Lower Jurassic. During the Jurassic, the three- fingered tetanuran theropods appeared, which gave rise to birds.

Conclusions

Saltriovenator zanellai gen. et sp. nov. is a new theropod dinosaur from the Lower Jurassic of Northern Italy. It represents the third named species of non-avian dinosaur from Italy, the first of Jurassic age. Saltriovenator shows a combination of ceratosaurian and tetanuran features, supporting close relationships between the two averostran lineages with the exclusion of coelophysoid-grade theropods. It also represents the first skeletal material supporting the occurrence of large and robustly-built predatory dinosaurs just at the aftermath of the Triassic–Jurassic boundary extinction events. Accordingly, the Italian ceratosaurian fills a stratigraphic and ecomorphological gap between the relatively more gracile coelophysoid-grade neotheropods (known from the Late Triassic to the Early Jurassic) and the large-bodied averostrans that occupied the majority of the apex predatory roles in the terrestrial ecosystems between the Middle Jurassic and the end of the Cretaceous.

The phylogenetic framework integrated with the new combination of features present in Saltriovenator dismisses the “II–III–IV homology pattern” in the interpretation of the tetanuran (and avian) hand, and suggests a complex process leading to the atrophied forelimb of later ceratosaurians. The evolution of a stocky and robust hand occurred in ceratosaurians before the relative shortening and the loss of predatory function: such a step-wise scenario raises intriguing perspectives on what adaptive and developmental factors led from a “Saltriovenator-like” condition to the aberrant condition present in Limusaurus and abelisaurids.

Cristiano Dal Sasso​, Simone Maganuco and Andrea Cau. 2018. The Oldest Ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, Sheds Light on the Evolution of the Three-fingered Hand of Birds.   PeerJ. 6:e5976.  DOI: 10.7717/peerj.5976

The oldest large-sized predatory dinosaur comes from the Italian Alps phys.org/news/2018-12-oldest-large-sized-predatory-dinosaur-italian.html via @physorg_com

Meet Saltriovenator: Oldest Known Big Predatory Dinosaur - Dead Things  bit.ly/2EuANJX

[Paleontology • 2019] Thanos simonattoi • A New Abelisauridae (Dinosauria: Theropoda) from São José do Rio Preto Formation, Upper Cretaceous of Brazil and Comments on the Bauru Group Fauna

Thanos simonattoi 

Delcourt & Iori, 2019

 DOI: 10.1080/08912963.2018.1546700 
Art by Deverson da Silva (Pepi).

ABSTRACT

Abelisaurid theropods are well-know from the Cretaceous of several parts of the Southern Hemisphere, including South America, Madagascar, and Africa, but also in India and Europe. Abelisaurids are high-diverse among other theropods with several cervicocephalic specializations reaching medium/large sizes. In the present contribution, we describe a new abelisaurid (Thanos simonattoi, gen. et sp. nov.) from the São José do Rio Preto Formation, Bauru Group, Brazil (Upper Cretaceous). Thanos differs from other theropods by having a well-developed keel becoming wider and deeper posteriorly on the ventral surface; two lateral small foramina separated by a relative wide wall on each lateral surface of the centrum, and well-developed and deep prezygapophyseal spinodiapophyseal fossae. The closed sutures between the axis and odontoid suggest that Thanos had reached a subadult/adult stage before death. Thanos is phylogenetically related to Brachyrostra abelisaurid. The keel on the ventral axial centrum in abelisauroids is here interpreted as a homoplastic condition that became more pronounced towards the phylogeny. The presence of well-developed keel in Thanos suggests that this taxon could be more derived than other abelisaurids. Finally, even though abelisaurids could reach large sizes, Thanos shared the environment with a larger theropod that was probably close to Megaraptora.

KEYWORDS: Theropods, Brachyrostra, vertebra, axis, Thanos simonattoi

Figure 4. An interpretative picture of the paleoenvironment of São José do Rio Preto Formation (Santonian, Upper Cretaceous). The picture shows two specimens of Thanos simonattoi (on the right side) and titanosaur sauropods (on the mid and left sides).

 Art by Deverson da Silva (Pepi).

Systematic palaeontology 

Dinosauria Owen, 1842 

Theropoda Marsh, 1881 

Ceratosauria Marsh 1884 

Abelisauroidea Bonaparte and Novas, 1985 

Abelisauridae Bonaparte and Novas, 1985 

Brachyrostra Canale et al. 2009 

Thanos simonattoi gen. et sp. nov. 

Etymology: Genus name from the Greek thánato, meaning death and from the Marvel’s character Thanos, the Conquer, created by Jim Starlin. Species name in honor of Sérgio Simonatto, the discoverer of the specimen.

.....

Conclusion:

In the present contribution, we have described a new abelisaurid from the São José do Rio Preto Formation, Upper Cretaceous of Brazil. Thanos simonattoi is distinguished from other abelisaurids by having a combination of features: a well-developed keel on the ventral surface becoming wider and deeper posteriorly; two lateral small foramina separated by a relative wide wall and two welldeveloped and deep prezygapophyseal spinodiapophyseal fossae. The keel on the ventral axial centrum of Thanos is interpreted as a homoplastic condition that became more pronounced towards the phylogeny, suggesting that this taxon could be more derived than other abelisaurids. The presence of a medium-sized abelisaurid in the São José do Rio Preto Formation increases the record of theropods, suggesting a complex carnivorous fauna during the Upper Cretaceous of Bauru Group. More findings are needed to better understand the morphology and the internal relationships of Thanos simonattoi.

Rafael Delcourt and Fabiano Vidoi Iori. 2019. A New Abelisauridae (Dinosauria: Theropoda) from São José do Rio Preto Formation, Upper Cretaceous of Brazil and Comments on the Bauru Group Fauna. Historical Biology: An International Journal of Paleobiology. DOI: 10.1080/08912963.2018.1546700 

Méndez AH, Novas FE and Iori FV. 2014. New Record of Abelisauroid Theropods from the Bauru Group (Upper Cretaceous), São Paulo State, Brazil. Revista Brasileira de Paleontologia. 17(1). Citeseer: 23–32.

 Researchgate.net/publication/265381596_New_records_of_abelisauroid_theropods_from_the_Bauru_Basin_Upper_Cretaceous_Sao_Paulo_State_Brazil

 waxing-paleontological.blogspot.com/2018/11/thanos-deserves-better.html 

[Paleontology • 2018] Large-sized Theropod Spinosaurus: An Important Component of the Carnivorous Dinosaur Fauna in southern Continents During the Cretaceous

Semi-aquatic paleoenvironmental reconstruction of Spinosaurus dinosaur during early Late Cretaceous:
 (A) Spinosaurus; (B) Mawsonia coelacanth fishes

in Candeiro, Gil & de Castro, 2018. 

 DOI: 10.1051/bsgf/2018010 

 (drawing Luciano Vidal)

Abstract 

The Early Cretaceous of North Africa has Spinosaurinae dinosaur remains such as Spinosaurus recorded in Algeria (Guir Basin, Kem Kem beds), Egypt (Bahariya Formation), Morocco (Kem Kem beds), and Tunisia (Ain El Guettar Formation). Until now, three possible Spinosaurus species were identified: Spinosaurus aegyptiacus, Spinosaurus sp. and Spinosaurus “B”. The occurrence of this genus in the Albian-Cenomanian rocks of Africa suggests that the temporal and geographic distribution of these spinosaurines is the largest one among all genera and species of megapredators from the middle Cretaceous of Africa. The fossil record of Spinosaurus from the Albian to the Cenomanian shows a 20 million year persistence of this genus in Gondwanan ecosystems.

Keywords: theropod dinosaur, distribution, Early Cretaceous, Africa

Fig. 3 Most complete Spinosaurus species skulls from early Late Cretaceous formations from Northern Africa.
 Spinosaurus aegyptiacus (from Stromer, 1915), BSP 1912 – dentary, A in lateral and B in dorsal views.
Spinosaurus cf. aegyptiacus (from Buffetaut and Ouaja, 2002), BM231 – rostral part of left dentary, C, in lateral and in D dorsal views.
 Spinosaurus marrocanus (nomen dubium) (Taquet and Russell, 1998) MNHM SAM 124 – left maxilary, E in lateral and F dorsal views.
Spinosaurus cf. S. aegyptiacus (from Dal Sasso et al., 2005) MSNM V4047 – left maxilary, G in lateral in dorsal view.

Fig. 5. Semi-aquatic paleoenvironmental reconstruction of Spinosaurus dinosaur during early Late Cretaceous: (A) Spinosaurus; (B) Mawsonia coelacanth fishes; (C) Araripemys turtle (drawing Luciano Vidal).

 Remarks: 

The middle Cretaceous strata of North Africa preserved an important record of the theropod Spinosaurus. Although their fossil remains are usually fragmented, most specimens show diagnostic characters of the genus Spinosaurus that are especially present in their conical and non-serrated teeth. The fossil record of this genus in North Africa shows a restricted geographic distribution between the Albian and the Cenomanian periods. Yet, when we consider their temporal distribution, it suggests that Spinosaurus had a significant geological history of nearly 20 million years, a lifespan unknown for other African megapredators species (e.g., Carcharodontosaurus – 18.5 mya [Candeiro et al., 2018]). The geological evidences indicate that Africa was an island during the main period of occurrence of this genus. The faunal composition of the spinosaurinae that inhabited the eastern coast of Africa is broadly comparable with the Cenomanian fossil records from western Africa, supporting the relative homogeneous composition of the taxon in these areas during this period. Additional studies and future field prospections in other localities could eventually reveal a wider distribution of this genus in other regions of Africa (e.g., Niger, Sudan) or even in western Europe and northern South America.

Carlos Roberto A. Candeiro, Lívia Motta Gil and Pedro Ernesto Pontes de Castro. 2018. Large-sized Theropod Spinosaurus: An Important Component of the Carnivorous Dinosaur Fauna in southern Continents During the Cretaceous. Bulletin de la Société Géologique de France. 189 (4-6): 15.  DOI: 10.1051/bsgf/2018010

Résumé – Spinosaurus (théropode de grande taille) : une composante importante de la faune de dinosaures carnivores des continents méridionaux au cours du Crétacé. Le Crétacé inférieur d’Afrique du Nord renferme des restes de dinosaures spinosaurinés, tels que Spinosaurus répertorié en Algérie (Bassin du Guir, Kem Kem beds), en Égypte (Formation Bahariya), au Maroc (Kem Kem beds) et en Tunisie (Formation Ain El Guettar). Jusqu’à ce jour, trois espèces de spinosaure sont reconnues : Spinosaurus aegyptiacus, Spinosaurus sp. et Spinosaurus “B”. La présence de ce genre dans les terrains albocénomaniens d’Afrique suggère que la répartition temporelle et géographique de ces spinosaurinés est la plus étendue de tous les genres et espèces de méga-prédateurs du Crétacé moyen d’Afrique. Le registre fossile de Spinosaurus, depuis l’Albien jusqu’au Cénomanien, indique une présence de 20 millions d’années pour ce genre dans les écosystèmes gondwaniens. 

Mots clés : théropode dinosaure / distribution / Crétacé inférieur / Afrique

[Paleontology • 2018] Dynamoterror dynastes • A New Tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Menefee Formation of New Mexico

Dynamoterror dynastes 

McDonald​, Wolfe & Dooley, 2018

Invictarx zephyri  

McDonald​ & Wolfe, 2018

 DOI:  10.7717/peerj.5749 twitter.com/WesternCenter 

Art by Brian Engh  twitter.com/GreyGriffon 

Abstract
The giant tyrannosaurids were the apex predators of western North America and Asia during the close of the Cretaceous Period. Although many tyrannosaurid species are known from numerous skeletons representing multiple growth stages, the early evolution of Tyrannosauridae remains poorly known, with the well-known species temporally restricted to the middle Campanian-latest Maastrichtian (∼77–66 Ma). The recent discovery of a new tyrannosaurid, Lythronax argestes, from the Wahweap Formation of Utah provided new data on early Campanian (∼80 Ma) tyrannosaurids. Nevertheless, the early evolution of Tyrannosauridae is still largely unsampled. We report a new tyrannosaurid represented by an associated skeleton from the lower Campanian Allison Member of the Menefee Formation of New Mexico. Despite fragmentation of much of the axial and appendicular skeleton prior to discovery, the frontals, a metacarpal, and two pedal phalanges are well-preserved. The frontals exhibit an unambiguous autapomorphy and a second potential autapomorphy that distinguish this specimen from all other tyrannosaurids. Therefore, the specimen is made the holotype of the new genus and species Dynamoterror dynastes. A phylogenetic analysis places Dynamoterror dynastes in the tyrannosaurid subclade Tyrannosaurinae. Laser-scanning the frontals and creation of a composite 3-D digital model allows the frontal region of the skull roof of Dynamoterror to be reconstructed.

 Reconstructed frontal complex of Dynamoterror dynastes.

 Missing elements reconstructed based upon Teratophoneus curriei (UMNH VP 16690) (Loewen et al., 2013). 

 Dynamoterror dynastes & Invictarx zephyri 

Art by Brian Engh 

twitter.com/WesternCenter 

 twitter.com/GreyGriffon 

Dinosauria Owen, 1842, sensu Baron, Norman & Barrett, 2017
Theropoda Marsh, 1881, sensu Baron, Norman & Barrett, 2017
Coelurosauria Huene, 1914, sensu Sereno, McAllister & Brusatte, 2005

Tyrannosauroidea Osborn, 1906,

 sensu Walker, 1964; Sereno, McAllister & Brusatte, 2005

Tyrannosauridae Osborn, 1906,

 sensu Sereno, McAllister & Brusatte, 2005

Tyrannosaurinae Osborn, 1906,

sensu Matthew & Brown, 1922; Sereno, McAllister & Brusatte, 2005

Dynamoterror dynastes gen. et sp. nov.

Holotype: UMNH VP 28348, incomplete associated skeleton including the left and right frontals, four fragmentary vertebral centra, fragments of dorsal ribs, right metacarpal II, supraacetabular crest of the right ilium, unidentifiable fragments of long bones, phalanx 2 of left pedal digit IV, and phalanx 4 of left pedal digit IV.

Etymology: Dynamoterror is derived from the transliterated Greek word dynamis (“power”) and the Latin word terror. The specific name, dynastes, is a Latin word meaning “ruler.” The intended meaning of the binomen is “powerful terror ruler.” The name also honors the binomen “Dynamosaurus imperiosus” (Osborn, 1905), a junior synonym of Tyrannosaurus rex (Osborn, 1905, 1906), but a particular childhood favorite of the lead author.

Locality: UMNH VP 28348 was collected in San Juan County, New Mexico, on land administered by the US BLM. Precise locality data are on file at UMNH and the BLM.

Horizon: UMNH VP 28348 was collected from outcrops of the Juans Lake Beds (Miller, Carey & Thompson-Rizer, 1991), upper part of the Allison Member, Menefee Formation; lower Campanian, Upper Cretaceous. Lucas et al. (2005) produced a radioisotopic date of 78.22 ± 0.26 Ma from a bentonite layer near the top of the Menefee Formation in the Gallina hogback in the eastern part of the San Juan Basin. In the part of the San Juan Basin where UMNH VP 28348 was collected, the overlying Cliff House Sandstone contains fossils of the ammonoid Baculites perplexus (Siemers & King, 1974), corresponding to between 78.0 and 78.5 Ma (Molenaar et al., 2002). According to the regional stratigraphic correlation chart of Molenaar et al. (2002), the Menefee Formation spans approximately 84.0–78.5 Ma, based upon correlations with marine biostratigraphic zones. This age range corresponds to uppermost Santonian—middle Campanian (Cohen et al., 2013).

Specific diagnosis (as for genus by monotypy): tyrannosaurine tyrannosaurid distinguished by two autapomorphies on the frontals: (1) prefrontonasal and prefrontolacrimal processes are in close proximity, separated only by a shallow notch; and (2) subrectangular, concave, laterally projecting caudal part of the postorbital suture, separated from the rostral part by a deep groove. The second autapomorphy should be treated as provisional, given the ontogenetic variation observed in this region of the frontal in other tyrannosaurids (Carr & Williamson, 2004) (see description of the lateral surface of the frontal below). In the context of the phylogenetic analysis of Carr et al. (2017), which is used herein, UMNH VP 28348 exhibits a feature that supports its affinities among derived tyrannosauroids (1561, “frontal, dorsotemporal fossa, medial extension, dorsal view: meets opposing fossa at the midline”; also present in Timurlengia euotica, Xiongguanlong baimoensis, B. sealeyi, and Tyrannosauridae), and a feature identified by Carr et al. (2017) as an unambiguous synapomorphy of “derived tyrannosaurines” (1571, “frontal, sagittal crest, form, dorsal and lateral views: present and pronounced (dorsoventrally tall), single structure”).
....

Conclusions: 

The description of Dynamoterror dynastes from the lower Campanian Allison Member of the Menefee Formation provides additional data on the morphology and diversity of early tyrannosaurines in Laramidia. However, additional discoveries are needed to elucidate the paleobiogeographic history of tyrannosaurines.





Andrew T. McDonald​, Douglas G. Wolfe and Alton C. Dooley Jr. 2018. A New Tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Menefee Formation of New Mexico. PeerJ. 6:e5749.  DOI:  10.7717/peerj.5749

 twitter.com/Hippodraco/status/1049634324729872385

 twitter.com/WesternCenter/status/1049632730361679873
Newly Discovered Tyrant Dinosaur Stalked Ancient New Mexico 
po.st/IteAl4 via @SmithsonianMag

Andrew T. McDonald​ and Douglas G. Wolfe. 2018. A New Nodosaurid Ankylosaur (Dinosauria: Thyreophora) from the Upper Cretaceous Menefee Formation of New Mexico. PeerJ. 6:e5435.  DOI:  10.7717/peerj.5435