In the February edition of Paleo News, we will look at several new discoveries:
Nhandumirim waldsangae, Cyamodus orientalis, Morus intrepidus, Shangyang gracilis, Culebratherium alemani and an enantiornithine bird foot preserved in amber!
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1- Nhandumirim waldsangae (Marsola et al, 2019)
Nhandumirim waldsangae is a new species of saurischian dinosaur from the late Triassic Santa Maria Formation, Brasil! What makes this dinosaur special is the fact that it represents one of the earliest theropods known, being the oldest in Brasil! For the paper click here.
Quoting from the 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 semi-articulated 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 semi-circular
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 being not 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 possibly represents the oldest
record of the group known in Brazil."
2- Cyamodus orientalis (Wang et al, 2019)
Cyamodus orientalis is a new species of placodont from the late Triassic of China, which, strangely enough, has more in common with European placodonts than Chinese ones!
Check out the original paper here.
Quoting from the abstract:
"The Triassic eastern Tethyan faunas have continued to yield numerous specimens of marine reptile taxa in recent years. Nevertheless, compared with other sauropterygian clades, the diversity of placodonts in these faunas is low, and remains of this group are relatively rare in the fossil assemblages. Here, we report a new cyamodontoid specimen (ZMNH M8820) from the early Late Triassic of Guizhou, south-west China. This specimen is a nearly complete skeleton lacking only the forelimbs. It is distinct from other known Chinese placodonts as it features a large skull with remarkably enlarged supratemporal fenestrae and a small and less regularly arranged carapace. Interestingly, this new specimen resembles the European Cyamodus more than any Chinese cyamodontoid genera, particularly when considering the dentition and other cranial morphology. However, it differs from known Cyamodus species in some cranial features (e.g. epipterygoid fully ossified, posttemporal fenestra large, dentition derived) and the absence of a separate pelvic shield. Furthermore, based on an updated data matrix of placodonts, our phylogenetic results support the affinity of this new Chinese specimen with European Cyamodus species, and a new species, Cyamodus orientalis sp. nov., is erected here. This new material represents the first reported Cyamodus specimen in the world that preserves a three-dimensional skull with an associated postcranial skeleton and it extends the distribution of this genus into the early Carnian of the eastern Tethys. The existence of Cyamodus, a nearshore taxon, in south-west China at this time reveals greater similarity and more rapid intercommunication than previously known between western and eastern Tethyan vertebrate faunas, although the palaeobiogeographical origin and migration history of Cyamodontidae – and of other clades of placodont reptiles – are still obscure due to the scarcity of material from the northern and southern margins of the Palaeotethys."
3- Morus intrepidus (Zanno et al, 2019)
Morus intrepidus is a new species of small tyranosauroid from the United States! It is the smallest tyranosauroid and the oldestb of the Cretaceous tyranosaurs of North America!
This discovery shrank the year gap of knowledge we had by 15 million years.
Here you can read the original paper.
Quoting from the abstract:"To date, eco-evolutionary dynamics in the ascent of tyrannosauroids to top predator roles have been obscured by a 70-million-year gap in the North American (NA) record. Here we report discovery of the oldest Cretaceous NA tyrannosauroid, extending the lineage by ~15 million years. The new taxon—Moros intrepidus gen. et sp. nov.—is represented by a hind limb from an individual nearing skeletal maturity at 6–7 years. With a ~1.2-m limb length and 78-kg mass, M. intrepidus ranks among the smallest Cretaceous tyrannosauroids, restricting the window for rapid mass increases preceding the appearance of colossal eutyrannosaurs. Phylogenetic affinity with Asian taxa supports transcontinental interchange as the means by which iconic biotas of the terminal Cretaceous were established in NA. The unexpectedly diminutive and highly cursorial bauplan of NA’s earliest Cretaceous tyrannosauroids reveals an evolutionary strategy reliant on speed and small size during their prolonged stint as marginal predators."
4- Shangyang gracilis (Wang & Zhou, 2019)
Shangyang gracilis is a new species of enantiornithine bird from the famous early Cretaceous beds of Liaoning, China. It has fused premaxillae bones, something not seen in previous of these birds.
Check the paper here.
Quoting from the abstract:
"We report a new small enantiornithine, Shangyang graciles gen. et sp. nov., based on a nearly complete and articulated skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, north-eastern China. Shangyang has premaxillae that are completely fused rostrally as well as along the frontal processes, a previously unrecognized condition in Early Cretaceous birds. As in three other enantiornithine taxa, Shangyang preserves a pair of craniolateral processes in the sternum. Phylogenetic analysis places Shangyang in a relatively derived position within Enantiornithes, suggesting that the craniolateral processes of the sternum evolved independently among some enantiornithine lineages from the condition seen in some basal ornithuromorphs. The craniolateral processes in modern birds provide the insertions of the M. sternocoracoideus that functions in the downstroke, which can also originate from the two cranialmost sternal ribs instead when these processes are absent. The altered origin of this muscle shows that diverse pectoral musculoskeletal modifications took place early in avian history."
5- Culebratherium alemani (Velez-Juarbe & Wood, 2019)
Culebratherium alemani is a new species of early Miocene dugongine found in the banks of the Panama Canal. It is Central America's oldest marine mammal!
Click here to read the paper.
Quoting from the abstract:
"Herein, we describe a new early Miocene dugongine from marine deposits of the Culebra Cut (Gaillard Cut) of the Panama Canal. The new taxon, Culebratherium alemani, gen. et sp. nov., represents one of the few records of late Aquitanian–early Burdigalian sirenians and the oldest sirenian from Central America. A phylogenetic analysis places Culebratherium in a clade with Dioplotherium cf. D. allisoni (Miocene of Brazil), Dioplotherium allisoni (Miocene of Baja California Sur, Mexico, and California, U.S.A.), and Dioplotherium sp. (Pliocene of Yucatan, Mexico). Similar to these taxa, Culebratherium is characterized by the presence of large incisor tusks, a premaxillary symphysis without a boss, a premaxilla-frontal suture forming a butt joint, and a moderately downturned rostrum. In addition, Culebratherium exhibits prominent occipital-cervical attachment sites for enlarged neck musculature. These features taken together are interpreted as adaptations for uprooting large, deeply buried seagrass rhizomes. Other dugongines with similar, yet convergent, dental and facial adaptations are known from earlier or coeval deposits in Puerto Rico, Florida, South Carolina, California, Baja California Sur, Brazil, and India and were constituents of sympatric paleocommunities of sirenians. Only fragmentary evidence of a second smaller and unidentifiable sirenian species is known from the Culebra Formation, but future discoveries may reveal a similar sympatric paleocommunity during the early Miocene of Panama. Finally, we used the results of the phylogenetic analysis to propose the new clade Pan-Sirenia as the most inclusive group consisting of stem and crown groups and redefine the Sirenia, Dugongidae, and Dugonginae clades."
6- Enantiornithine bird foot preserved in amber
A fully feathered enantiornithine bird foot found in mid Cretaceous (approximatly 99 million years ago) Burmese amber, showing extraordinary preservation was described! However, a new taxon was not erected.
You can read the paper here.
Quoting from the abstract:
"Over the last three years, Burmese amber (~99 Ma, from Myanmar) has provided a series of immature enantiornithine skeletal remains preserved in varying developmental stages and degrees of completeness. These specimens have improved our knowledge based on compression fossils in Cretaceous sedimentary rocks, adding details of three-dimensional structure and soft tissues that are rarely preserved elsewhere. Here we describe a remarkably well-preserved foot, accompanied by part of the wing plumage. These body parts were likely dismembered, entering the resin due to predatory or scavenging behaviour by a larger animal. The new specimen preserves contour feathers on the pedal phalanges together with enigmatic scutellae scale filament (SSF) feathers on the foot, providing direct analogies to the plumage patterns observed in modern birds, and those cultivated through developmental manipulation studies. Ultimately, this connection may allow researchers to observe how filamentous dinosaur ‘protofeathers’ developed—testing theories using evolutionary holdovers in modern birds."
Nhandumirim waldsangae, Cyamodus orientalis, Morus intrepidus, Shangyang gracilis, Culebratherium alemani and an enantiornithine bird foot preserved in amber!
Don't forget to follow me on Instagram!
1- Nhandumirim waldsangae (Marsola et al, 2019)
 |
| (Credit: Marsola et al, 2019) |
Quoting from the 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 semi-articulated 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 semi-circular
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 being not 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 possibly represents the oldest
record of the group known in Brazil."
2- Cyamodus orientalis (Wang et al, 2019)
Cyamodus orientalis is a new species of placodont from the late Triassic of China, which, strangely enough, has more in common with European placodonts than Chinese ones!
 |
| (Credit: Wang et al, 2019) |
Check out the original paper here.
Quoting from the abstract:
"The Triassic eastern Tethyan faunas have continued to yield numerous specimens of marine reptile taxa in recent years. Nevertheless, compared with other sauropterygian clades, the diversity of placodonts in these faunas is low, and remains of this group are relatively rare in the fossil assemblages. Here, we report a new cyamodontoid specimen (ZMNH M8820) from the early Late Triassic of Guizhou, south-west China. This specimen is a nearly complete skeleton lacking only the forelimbs. It is distinct from other known Chinese placodonts as it features a large skull with remarkably enlarged supratemporal fenestrae and a small and less regularly arranged carapace. Interestingly, this new specimen resembles the European Cyamodus more than any Chinese cyamodontoid genera, particularly when considering the dentition and other cranial morphology. However, it differs from known Cyamodus species in some cranial features (e.g. epipterygoid fully ossified, posttemporal fenestra large, dentition derived) and the absence of a separate pelvic shield. Furthermore, based on an updated data matrix of placodonts, our phylogenetic results support the affinity of this new Chinese specimen with European Cyamodus species, and a new species, Cyamodus orientalis sp. nov., is erected here. This new material represents the first reported Cyamodus specimen in the world that preserves a three-dimensional skull with an associated postcranial skeleton and it extends the distribution of this genus into the early Carnian of the eastern Tethys. The existence of Cyamodus, a nearshore taxon, in south-west China at this time reveals greater similarity and more rapid intercommunication than previously known between western and eastern Tethyan vertebrate faunas, although the palaeobiogeographical origin and migration history of Cyamodontidae – and of other clades of placodont reptiles – are still obscure due to the scarcity of material from the northern and southern margins of the Palaeotethys."
3- Morus intrepidus (Zanno et al, 2019)
Morus intrepidus is a new species of small tyranosauroid from the United States! It is the smallest tyranosauroid and the oldestb of the Cretaceous tyranosaurs of North America!
This discovery shrank the year gap of knowledge we had by 15 million years.
Here you can read the original paper.
 |
| (Credit: Zanno et al, 2019) |
4- Shangyang gracilis (Wang & Zhou, 2019)
Shangyang gracilis is a new species of enantiornithine bird from the famous early Cretaceous beds of Liaoning, China. It has fused premaxillae bones, something not seen in previous of these birds.
Check the paper here.
| (Credit: Wang & Zou, 2019) |
Quoting from the abstract:
"We report a new small enantiornithine, Shangyang graciles gen. et sp. nov., based on a nearly complete and articulated skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, north-eastern China. Shangyang has premaxillae that are completely fused rostrally as well as along the frontal processes, a previously unrecognized condition in Early Cretaceous birds. As in three other enantiornithine taxa, Shangyang preserves a pair of craniolateral processes in the sternum. Phylogenetic analysis places Shangyang in a relatively derived position within Enantiornithes, suggesting that the craniolateral processes of the sternum evolved independently among some enantiornithine lineages from the condition seen in some basal ornithuromorphs. The craniolateral processes in modern birds provide the insertions of the M. sternocoracoideus that functions in the downstroke, which can also originate from the two cranialmost sternal ribs instead when these processes are absent. The altered origin of this muscle shows that diverse pectoral musculoskeletal modifications took place early in avian history."
5- Culebratherium alemani (Velez-Juarbe & Wood, 2019)
Culebratherium alemani is a new species of early Miocene dugongine found in the banks of the Panama Canal. It is Central America's oldest marine mammal!
Click here to read the paper.
 |
| (Credit: Velez_Juarbe & Wood, 2019) |
Quoting from the abstract:
"Herein, we describe a new early Miocene dugongine from marine deposits of the Culebra Cut (Gaillard Cut) of the Panama Canal. The new taxon, Culebratherium alemani, gen. et sp. nov., represents one of the few records of late Aquitanian–early Burdigalian sirenians and the oldest sirenian from Central America. A phylogenetic analysis places Culebratherium in a clade with Dioplotherium cf. D. allisoni (Miocene of Brazil), Dioplotherium allisoni (Miocene of Baja California Sur, Mexico, and California, U.S.A.), and Dioplotherium sp. (Pliocene of Yucatan, Mexico). Similar to these taxa, Culebratherium is characterized by the presence of large incisor tusks, a premaxillary symphysis without a boss, a premaxilla-frontal suture forming a butt joint, and a moderately downturned rostrum. In addition, Culebratherium exhibits prominent occipital-cervical attachment sites for enlarged neck musculature. These features taken together are interpreted as adaptations for uprooting large, deeply buried seagrass rhizomes. Other dugongines with similar, yet convergent, dental and facial adaptations are known from earlier or coeval deposits in Puerto Rico, Florida, South Carolina, California, Baja California Sur, Brazil, and India and were constituents of sympatric paleocommunities of sirenians. Only fragmentary evidence of a second smaller and unidentifiable sirenian species is known from the Culebra Formation, but future discoveries may reveal a similar sympatric paleocommunity during the early Miocene of Panama. Finally, we used the results of the phylogenetic analysis to propose the new clade Pan-Sirenia as the most inclusive group consisting of stem and crown groups and redefine the Sirenia, Dugongidae, and Dugonginae clades."
6- Enantiornithine bird foot preserved in amber
A fully feathered enantiornithine bird foot found in mid Cretaceous (approximatly 99 million years ago) Burmese amber, showing extraordinary preservation was described! However, a new taxon was not erected.
You can read the paper here.
 |
| (Credit: Xing et al, 2019) |
Quoting from the abstract:
"Over the last three years, Burmese amber (~99 Ma, from Myanmar) has provided a series of immature enantiornithine skeletal remains preserved in varying developmental stages and degrees of completeness. These specimens have improved our knowledge based on compression fossils in Cretaceous sedimentary rocks, adding details of three-dimensional structure and soft tissues that are rarely preserved elsewhere. Here we describe a remarkably well-preserved foot, accompanied by part of the wing plumage. These body parts were likely dismembered, entering the resin due to predatory or scavenging behaviour by a larger animal. The new specimen preserves contour feathers on the pedal phalanges together with enigmatic scutellae scale filament (SSF) feathers on the foot, providing direct analogies to the plumage patterns observed in modern birds, and those cultivated through developmental manipulation studies. Ultimately, this connection may allow researchers to observe how filamentous dinosaur ‘protofeathers’ developed—testing theories using evolutionary holdovers in modern birds."
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