Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-preserved cranial remains. A new sauropod dinosaur from the Early Cretaceous of Brazil represents the earliest advanced titanosaurian known to date, demonstrating that the initial diversification of advanced titanosaurians was well under way at least 30 million years before their known radiation in the latest Cretaceous. The new taxon also preserves the most complete skull among titanosaurians, further revealing that their low and elongated diplodocid-like skull morphology appeared much earlier than previously thought.

Context: In the Americas, the main representatives of the family Elapidae are coral snakes of the genus Micrurus, of which 33 species are in Brazil. They are the smallest cause of venomous snakebite in Brazil. We analyzed literature reports of coral snake bites in Brazil from 1867 to 2014, and provide a brief review of case series and reports of coral snake bites in the Americas in general. Methods: Only reports with clinical descriptions of envenomation were included. The variables recorded included identification of the offending snake, patient's age, sex, bite site, clinical manifestations, treatment, including antivenom and anticholinesterase drugs, and general evolution of the cases. 30 published reports describing bites caused by Micrurus spp. in Brazil were identified and involved 194 distinct cases. Since no information on the clinical manifestations was available in 44 cases, the analysis was restricted to 25 reports (150 cases). Results: Most patients were from southern (61.3%; primarily Santa Catarina state, 60%) and southeastern (20%) Brazil and were male (70.7%), with a median age of 27 years (interquartile interval = 18 to 40 years). The offending snakes were described in 59 cases (M. corallinus 36, M. frontalis 12, M. lemniscatus 5, M. hemprichi 2, M. filiformis 1, M. ibiboboca 1, M. spixii 1 and M. surinamensis 1); in 22 cases only the genus (Micrurus spp.) was reported. Of the 143 cases in which the bite site was recorded, most involved the hands (46.2%) and feet (26.6%). The main clinical features were local numbness/paresthesia (52.7%), local pain (48%), palpebral ptosis (33.3%), dizziness (26.7%), blurred vision (20.7%), weakness (20%), slight local edema (16%), erythema (16%), dysphagia (14.7%), dyspnea (11.3%), inability to walk (10.7%), myalgia (9.3%), salivation (8%) and respiratory failure (4.3%). Fang marks were described in 47.3% of cases and 14% of bites were classified as asymptomatic. A slight increase in total blood creatine kinase was reported in 3 children, suggesting mild myotoxicity. Therapeutic procedures included coral snake antivenom (77.3%), anticholinesterase drugs (6%), and mechanical ventilation (3.3%). Two patients reported in 1933 developed paralysis/respiratory failure and died 6 h and 17 h post-bite. Four more deaths probably caused by coral snakes were reported (2 in 1867, 1 in 1959, 1 in 1962), but no clinical information was available. Discussion: Neuromuscular blockade was the hallmark of systemic envenomation by Micrurus spp., with signs of myasthenia such as weakness and ptosis that may evolve to paralysis and respiratory failure. Local features, mainly numbness/paresthesia and pain, were frequently reported, with the pain being intense in some cases. Although myotoxicity has been detected in experimental studies with Micrurus spp. venoms, few human reports described laboratory findings compatible with myotoxicity. Conclusion: Most coral snake bites reported in Brazil were caused by M. corallinus and M. frontalis, with several patients showing signs of acute myasthenia. Serious complications such as paralysis with respiratory failure were observed but comparatively rare. The deaths occurred where respiratory support (mechanical ventilation) was unavailable when needed.

Venom gland transcriptomes and proteomes of six Micrurus taxa (M. corallinus, M. lemniscatus carvalhoi, M. lemniscatus lemniscatus, M. paraensis, M. spixii spixii, and M. surinamensis) were investigated, providing the most comprehensive, quantitative data on Micrurus venom composition to date, and more than tripling the number of Micrurus venom protein sequences previously available. The six venomes differ dramatically. All are dominated by 2–6 toxin classes that account for 91–99% of the toxin transcripts. The M. s. spixii venome is compositionally the simplest. In it, three-finger toxins (3FTxs) and phospholipases A₂ (PLA₂s) comprise >99% of the toxin transcripts, which include only four additional toxin families at levels ≥0.1%. Micrurus l. lemniscatus venom is the most complex, with at least 17 toxin families. However, in each venome, multiple structural subclasses of 3FTXs and PLA₂s are present. These almost certainly differ in pharmacology as well. All venoms also contain phospholipase B and vascular endothelial growth factors. Minor components (0.1–2.0%) are found in all venoms except that of M. s. spixii. Other toxin families are present in all six venoms at trace levels (<0.005%). Minor and trace venom components differ in each venom. Numerous novel toxin chemistries include 3FTxs with previously unknown 8- and 10-cysteine arrangements, resulting in new 3D structures and target specificities. 9-cysteine toxins raise the possibility of covalent, homodimeric 3FTxs or heterodimeric toxins with unknown pharmacologies. Probable muscarinic sequences may be reptile-specific homologs that promote hypotension via vascular mAChRs. The first complete sequences are presented for 3FTxs putatively responsible for liberating glutamate from rat brain synaptosomes. Micrurus C-type lectin-like proteins may have 6–9 cysteine residues and may be monomers, or homo- or heterodimers of unknown pharmacology. Novel KSPIs, 3× longer than any seen previously, appear to have arisen in three species by gene duplication and fusion. Four species have transcripts homologous to the nociceptive toxin, (MitTx) α-subunit, but all six species had homologs to the β-subunit. The first non-neurotoxic, non-catalytic elapid phospholipase A₂s are reported. All are probably myonecrotic. Phylogenetic analysis indicates that the six taxa diverged 15–35 million years ago and that they split from their last common ancestor with Old World elapines nearly 55 million years ago. Given their early diversification, many cryptic micrurine taxa are anticipated.