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.

References:

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)

Liaodactylus primus and the ecological evolution of Pterodactyloidea.

Skull of the newfound species Liaodactylus primus (Credit: Chang-Fu Zhou)

Skull of the newfound species Liaodactylus primus (Credit: Chang-Fu Zhou)

Pterosaurs are an extinct monophyletic clade of ornithodiran archosauromorph reptiles from the Late Triassic to Late Cretaceous. The group achieved high levels of morphologic and taxonomic diversity during the Mesozoic, with more than 150 species recognized so far. During their 149 million year history, the evolution of pterosaurs resulted in a variety of eco-morphological adaptations, as evidenced by differences in skull shape, dentition, neck length, tail length and wing span. Pterosaurs have traditionally been divided into two major groups, “rhamphorhynchoids” and “pterodactyloids”. Rhamphorhynchoids are characterized by a long tail, and short neck and metacarpus. Pterodactyloids have a much larger body size range, an elongated neck and metacarpus, and a relatively short tail. Darwinopterus from the early Late Jurassic of China appear to be a transitionary stage that partially fills the morphological gap between rhamphorhynchoids and pterodactyloids.

Pterodactyloidea, the most species-diverse group of pterosaurs, ruled the sky from Late Jurassic to the end of Cretaceous. Liaodactylus primus, a new specimen, discovered in northeast China’s Liaoning province, documents the only pre-Tithonian (145–152 Ma) pterodactyloid known with a complete skull, shedding new light on the origin of the Ctenochasmatidae, a group of exclusive filter feeders, and the timing of the critical transition from fish-catching to filter-feeding, a major ecological shift in the early history of the pterodactyloid clade. The holotype specimen is a nearly complete skull (133 mm long) and mandibles, with the first two cervical vertebrae preserved in articulation with the skull. The elongation of the rostrum, almost half the length of the skull, is accompanied by a significant increase in the number of marginal teeth, giving a total of 152 teeth in both sides of the upper and lower jaws. The teeth are closely spaced to form a ‘comb dentition’, a filter-feeding specialization.

Pterodaustro guinazui cast (Museo Argentino de Ciencias Naturales)

Pterodaustro guinazui cast (Museo Argentino de Ciencias Naturales)

Liaodactylus is the oldest known ctenochasmatid, predating the previously Tithonian (152 Ma) record (Gnathosaurus and Ctenochasma from Germany) by at least 8–10 Myr . The Ctenochasmatidae, represents a long-ranged clade (160–100 Ma), and the only pterodactyloid clade that crossed the Jurassic-Cretaceous transition. The group includes the Early Cretaceous Pterodaustro from Argentina. Popularly called the ‘flamingo pterosaur’, Pterodaustro represents the most remarkable filter-feeding pterosaur known from the fossil record, with a huge number (more than 1000) of densely spaced ‘teeth’ (elastic bristles) in its lower jaws, for filtering small crustaceans, microscopic plankton or algae from open water along lake shores.

Pterosaurs display an extraordinary eco-morphological disparity in feeding adaptations, expressed in skull, jaws and dentition. The Late Triassic Eopterosauria, the basalmost pterosaur clade, were mainly insectivorous. Jurassic insectivores include the Dimorphodontia, Campylognathoididae and Darwinoptera, whereas the Anurognathidae were the only Jurassic insectivores that survived the Jurassic–Cretaceous transition, but became extinct in the Early Cretaceous. The rise of the ctenochasmatid clade was the first major ecological shift in pterosaur evolution from insectivorous-piscivorous to filter-feeding. During Cretaceous time,  the Eupterodactyloidea, a group of advanced pterodactyloids, engaged in a variety of feeding adaptations, including filter-feeding, fish-eating, carnivory and scavenging, herbivory including frugivory, durophagy and omnivory. The Early Cretaceous tapejarids may have been herbivorous, while the pteranodontids, with large skull but tapering and toothless jaws were suitable for seizing fish in open-water environments. Finally, the Late Cretaceous azhdarchids have been hypothesized as foragers feeding on small animals and carrion in diverse terrestrial environments.

Time-calibrated cladogram showing stratigraphic range, eco-morphological diversity of pterosaur clades. (Adapted from Zhou et al., 2017)

Time-calibrated cladogram showing stratigraphic range, eco-morphological diversity of pterosaur clades. (Adapted from Zhou et al., 2017)

References:

Chang-Fu Zhou, Ke-Qin Gao, Hongyu Yi, Jinzhuang Xue, Quanguo Li, Richard C. Fox, Earliest filter-feeding pterosaur from the Jurassic of China and ecological evolution of Pterodactyloidea, 

Andres, B., Clark, J., & Xu, X. (2014). The earliest pterodactyloid and the origin of the group. Current Biology, 24(9), 1011-1016.

WITTON, M. P., 2010 Pteranodon and beyond: the history of giant pterosaurs from 1870 onwards. In: Moody, R.T.J., Buffetaut, E., Naish, D., Martill, D.M. (Eds.), Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications 343, 287–311.

 

Christmas edition: Geologizing with Dickens, part II.

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Charles Dickens at his desk, by George Herbert Watkins (National Portrait Gallery. From Wikimedia Commons)

Charles Dickens (1812- 1870) revitalized the traditions of Christmas, and to Victorian England, Dickens was Christmas. He had only 31, when began to write A Christmas Carol. The novella tells the story of  Ebenezer Scrooge, a bitter old man who finds salvation through the visits of the three Ghosts of Christmas (Ghost of Christmas Past, Ghost of Christmas Present, and Ghost of Christmas Yet to Come). But Dickens also contributed to the popularity of geology in the nineteenth century. Among his friends were Richard Owen and Sir Roderick Murchison. For Dickens, the ideal science is Geology. In his review of Hunt’s Poetry of Science, he wrote: “Science has gone down into the mines and coal-pits, and before the safety-lamp the Gnomes and Genii of those dark regions have disappeared … Sirens, mermaids, shining cities glittering at the bottom of quiet seas and in deep lakes, exist no longer; but in their place, Science, their destroyer, shows us whole coasts of coral reef constructed by the labours of minute creatures; points to our own chalk cliffs and limestone rocks as made of the dust of myriads of generations of infinitesimal beings that have passed away; reduces the very element of water into its constituent airs, and re-creates it at her pleasure…” (London Examiner, 1848).

In 1846, Dickens visited Naples and climbed the Mount Vesuvius. He described that experience in Pictures from Italy. He wrote: “Stand at the bottom of the great market-place of Pompeii, and look up the silent streets, through the ruined temples of Jupiter and Isis, over the broken houses with their inmost sanctuaries open to the day, away to Mount Vesuvius, bright and snowy in the peaceful distance; and lose all count of time, and heed of other things, in the strange and melancholy sensation of seeing the Destroyed and the Destroyer making this quiet picture in the sun.”

An eruption of Vesuvius circa 1845. Credit: Enrico La Pira.

An eruption of Vesuvius circa 1845. Credit: Enrico La Pira.

Mount Vesuvius is a stratovolcano, consisting of an external truncated cone, the extinct Mt. Somma,  a smaller cone represented by Vesuvius. For this reason, the volcano is also called Somma-Vesuvio. It was formed by the collision of two tectonic plates, the African and the Eurasian. When Mount Vesuvius erupted in 79 AD released deadly cloud of ash and molten rocks, and lasted eight days, burying and destroying the cities of Pompeya, Herculaneum and Stabiae. Vesuvius has the world’s oldest volcano observatory, established in 1845, and Dickens’s own magazine Household Words, frequently ran travel pieces describing the ascent and descent of Vesuvius, alongside trips to Pompei.

The same year, Dickens began to to write Dombey and Son, using his experiences in Italy to describe a violent eruption: “Hot springs and fiery eruptions, the usual attendants upon earthquakes, lent their contributions of confusion to the scene. Boiling water hissed and heaved within dilapidated walls; whence, also, the glare and roar of flames came issuing forth; and mounds of ashes blocked up rights of way, and wholly changed the law and custom of the neighbourhood”. 

Benjamin Waterhouse Hawkins unveiled the first ever sculptures of Iguanodons.

Benjamin Waterhouse Hawkins unveiled the first ever sculptures of Iguanodons.

It was an exciting time full of discoveries and the concept of an ancient Earth became part of the public understanding. The study of the Earth was central to the economic and cultural life of the Victorian Society and Literature influenced the pervasiveness of geological thinking. So when the Crystal Palace was reconstructed at Sydenham in 1854, Dickens and his Household Words were very enthusiastic. Megalosaurus became so popular that is mentioned in his novel Bleak House. In this novel the dinosaurs uncovered by the railway in Dombey and Son move centre stage: “Implacable November weather. As much mud in the streets as if the waters had but newly retired from the face of the earth, and it would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up Holborn Hill.”  

In Bleak House and Dombey and Son, Dickens encourage reader to perceive the scene of the city as a geological fragment of a much broader spatial and temporal vision. In his last novel Our Mutual Friend (1864–65), Mr Venus, the taxidermist was slightly based on Richard Owen. By the time when Dickens wrote this novel, Owen was the curator of the Hunterian Museum of the Royal College of Surgeons. Our Mutual Friend, also exhibits  traces of the work of Lyell, Jean-Baptiste Lamarck, and Darwin.

References:

A. BUCKLAND, ‘“The Poetry of Science”: Charles Dickens, Geology and Visual and Material Culture in Victorian London’, Victorian Literature and Culture, 35 (2007), 679–94 (p. 680).

A. BUCKLAND. Novel Science: Fiction and the Invention of Nineteenth-Century Geology. Chicago, IL and London: University of Chicago Press, 2013. 400 pp. 9 plts. $45.00. ISBN 978-0-226-07968-4

High variation in postnatal development of Early Dinosaurs.

Cleveland Museum of Natural History Coelophysis block, originally AMNH Block XII collected in 1948 by Colbert and crew

Cleveland Museum of Natural History Coelophysis block, originally AMNH Block XII collected in 1948 (From Wikimedia Commons)

Birds originated from a theropod lineage more than 150 million years ago. Their evolutionary history is one of the most enduring and fascinating debates in paleontology. They are members of the theropod dinosaur subgroup Coelurosauria, a diverse clade that includes tyrannosauroids and dromaeosaurids, among others. Features like “hollow” bones and postcranial skeletal pneumaticity, feathers, a unique forelimb digit formula, endothermy, and rapid growth rate arose in non-avian dinosaurs in a gradual process occurring over tens of millions of years.

In contrast with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development, suggesting that this avian style of development must have evolved after its most recent common ancestor with crocodylians but before the origin of Aves. Most studies indicates that the low levels of variation that characterize avian ontogeny were present in close non-avian relatives as well.

Two C. bauri casts mounted at the Denver Museum of Nature and Science (From Wikimedia Commons)

Two C. bauri casts mounted at the Denver Museum of Nature and Science (From Wikimedia Commons)

Compared with birds, the theropod Coelophysis bauri possess a large amount of intraspecific variation. Coelophysis bauri is the type species of the genus Coelophysis, a group of small, slenderly-built, ground-dwelling, bipedal carnivores, that lived approximately 203 million years ago during the latter part of the Triassic Period in what is now the southwestern United States. Using this taxon to interpret development among early dinosaurs, geoscientists Christopher Griffin and Sterling Nesbitt discovered that the earliest dinosaurs had a far higher level of variation in growth patterns between individuals than crocodiles and birds. The presence of scars on the bones left from muscle attachment and marks where bones had fused together helped the researchers assess how mature the animals were compared with their size.

Body size and extinction risk have been found to be related in various vertebrate groups, therefore a high level of variation within a species may be advantageous in an ecologically unstable environment and may have contributed to the early success of dinosaurs relative to many pseudosuchian clades in the latest Triassic and through the End-Triassic Mass Extinction into the Early Jurassic.

References:

Christopher T. Griffin and Sterling J. Nesbitt, Anomalously high variation in postnatal development is ancestral for dinosaurs but lost in birds. PNAS 2016 : 1613813113v1-201613813.

Brusatte SL, Lloyd GT, Wang SC, Norell MA (2014) Gradual assembly of avian body plan culminated in rapid rates of evolution across the dinosaur-bird transition. Curr Biol 24(20):2386–2392

Puttick, M. N., Thomas, G. H. and Benton, M. J. (2014), HIGH RATES OF EVOLUTION PRECEDED THE ORIGIN OF BIRDS. Evolution, 68: 1497–1510. doi: 10.1111/evo.12363 A.

A brief introduction to the Early dinosaurs from Argentina.

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Articulated skeleton of Eoraptor lunensi (From Sereno 2013)

The oldest record of Argentinean dinosaurs comes from the Ischigualasto Formation, NW Argentina, dated from 231.4 Ma to 225.9 Ma. Adolf Stelzner in 1889 published the first data on the geology of Ischigualasto, but it was not until 1911 that Guillermo Bodenbender briefly refers to the fossils of the site. In the early 40′s, Joaquin Frenguelli, initiates a geological survey in the western margin of the basin. Later, in 1943, Angel Cabrera described fragmentary therapsid fossils. However, intensive paleontological study of the Ischigualasto and Chañares Formations, began only in the late 1950s.

The Ischigualasto Formation has 300–700 m of mudstone, sandstone, conglomerate, and basalt, and consists of four lithostratigraphic members which in ascending order include the La Peña Member, the Cancha de Bochas Member, the Valle de la Luna Member, and the Quebrada de la Sal Member. Eight valid species of dinosaurs are known from the Ischigualasto Formation: Pisanosaurus mertii, Herrerasaurus ischigualastensis, Sanjuansaurus gordilloi, Eodromaeus murphi, Eoraptor lunensis, Panphagia protos, and Chromogisaurus novasi.

 

Skull of Herrerasaurus ischigualastensis (Sereno, 2013)

Skull of Herrerasaurus ischigualastensis (Sereno, 2013)

Pisanosaurus mertii is a small specimen, know by an incomplete maxilla and lower jaw fragments bearing teeth, vertebrae, incomplete hind limb, and the impression of the pelvis. Described in 1967 by Rodolfo CasamiquelaPisanosaurus is considered as the oldest known ornithischian.

Herrerasaurus ischigualastensis was described by Osvaldo Reig in 1963. The taxon is one of the best known Triassic dinosaurs and the largest dinosaur of the Ischigualasto Formation. Herrerasaurus was fully bipedal, with strong hind limbs, short thighs and long feet. The skull has a rectangular profile and a transversely narrow snout (Sereno and Novas, 1992). The presence of two sacral vertebrae and lack of brevis fossa made Herrerasaurus, and other herrerasaurids, a controversial group.

Sanjuansaurus gordilloi is similar to Herrerasaurus ischigualastensis, although more gracile and possessing short and straight pubis among other differences (Alcober & Martínez, 2010). It’s known from one specimen that preserves left maxilla, partial axial column, scapulae, left ulna, ungual of manual digit III, partial left ilium and pubis, both femora and tibiae, right fibula, right astragalus and calcaneum, and left metatarsal.

Skull and skeleton of Eodromaeus murphi (PVSJ 560). Scale bar equals 10 cm.

Skull and skeleton of Eodromaeus murphi
(PVSJ 560). Scale bar equals 10 cm.

Eodromaeus murphi is a small species with a total length of about 1.2 metres, known from five specimens. The trunk was long and slender, and forelimbs were shorter than the hindlimbs. The skull is relatively low and lightly built with a relatively spacious antorbital fenestra.  A phylogenetic analysis places Eodromaeus within Theropoda as the sister taxon to Neotheropoda

Eoraptor lunensis is known from eight specimens, including the holotype that preserves most of the skeleton. Eoraptor had a slender body with an estimated weight of about 10 kilograms. The lightly built skull has a slightly enlarged external naris and the premaxilla is observed to have a slender posterolateral process. The long bones of the hind limb have more robust shafts than those of Eodromaeus, although in both genera the tibia remains slightly longer than the femur (Sereno et al., 2013). Initially considered a basal theropod, the sauropodomorph affinity of Eoraptor has been strengthened after the publication of its anatomy in 2013.

Panphagia protos is a small species, known from one partial skeleton including several skull bones, lower jaw, and partial axial skeleton. The specimen is an immature individual with an estimated body length of approximately 1.30 m. It was originally proposed as the most basal sauropodomorph (Martinez and Alcober, 2009)

Chromogisaurus novasi is also similar in size to Eoraptor lunensis. It’s known from a partial skeleton lacking the skull. It includes elements of the front and hind limbs, the pelvis and two caudal vertebrae.

References:

Martín D. EZCURRA & Ricardo N. MARTÍNEZ (2016), Dinosaur precursors and early dinosaurs from Argentina., In book: Historia Evolutiva y Paleobiogeografía de los Vertebrados de América del Sur, Publisher: Contribuciones del MACN, Editors: F. Agnolíin, G.L. Lio, F. Brissón Egli, N.R. Chimento, F. Novas, pp.97-107

Reig, O.A. (1963). “La presencia de dinosaurios saurisquios en los “Estratos de Ischigualasto” (Mesotriásico Superior) de las provincias de San Juan y La Rioja (República Argentina)”. Ameghiniana (in Spanish). 3 (1): 3–20.

Sereno, P.C.; Novas, F.E. (1992). “The complete skull and skeleton of an early dinosaur”. Science. 258 (5085): 1137–1140.

Ricardo N. Martinez; Paul C. Sereno; Oscar A. Alcober; Carina E. Colombi; Paul R. Renne; Isabel P. Montañez; Brian S. Currie (2011). “A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea”. Science. 331 (6014): 206–210. doi:10.1126/science.1198467

Martinez RN, Alcober OA (2009) A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha. PLoS ONE 4(2): e4397. doi:10.1371/journal.pone.0004397

Ezcurra, M. D. 2010. “A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny.” Journal of Systematic Palaeontology 8: 371-425.

 

Dracorex hogwartsia: A fantastic beast and where to find it.

The cover of the book Fantastic Beasts and Where to Find Them.

The cover of the book Fantastic Beasts and Where to Find Them.

It has been nearly 20 years since Harry Potter and The Philosopher’s Stone was released. Written by  J. K. Rowling, the book was the first of a saga about a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley, all of whom are students at Hogwarts School of Witchcraft and Wizardry. The original seven books were adapted into an eight-part film series. In 2011, the last part of the saga, Harry Potter and the Deathly Hallows Part 2 debuted in cinemas worldwide. Now, the magic world of Harry Potter is returning to the big screen. “Fantastic Beasts and where to find it” takes place in the Harry Potter Universe almost 80 years before Harry himself enters the scene. The story follows Newt Scamander, a British wizard and magic-zoologist. After being expelled from Hogwarts, Scamander joined to the Ministry of Magic and spent two years in the Office for House-Elf Relocation before being transferred to the Beast Division. Due to his extensive knowledge of magical creatures, Augustus Worme of Obscurus Books commissioned Scamander to write the first edition of “Fantastic Beasts and Where to Find Them”.

Dracorex skeletal reconstruction (Dracorex hogwartsia) is in the permanent collection of The Children’s Museum of Indianapolis.

Skeletal reconstruction of Dracorex hogwartsia in the permanent collection of The Children’s Museum of Indianapolis (From Wikimedia Commons)

Scamander travelled to numerous cities doing research for his book and in 1926 he arrived to New York, a city full of great economic inequality and where wizards were forced to hide. Years later, Scamander worked extensively with the Dragon Research and Restraint Bureau, which led him on expeditions all over the world, collecting information for new editions of Fantastic Beasts. Published in 1927, Fantastic Beasts became an approved textbook at Hogwarts. Among the beasts included in the book are Acromantula, the Basilisk, Manticore and different types of Dragons. Most probably, Scamander would have included Dracorex hogwartsia in a new edition of the book.

Dracorex is known from one nearly complete skull discovered in the Upper Cretaceous Hell Creek Formation of South Dakota and donated to the Children’s Museum of Indianapolis in 2004. It was described by Bob Bakker and Robert Sullivan in 2006. The  name was taken from the Latin words for dragon, draco, and king, rex, and the latinized name for Hogwarts, hogwartsia. 

Dracorex skull (Image credit: The Children’s Museum of Indianapolis)

Dracorex skull (Image credit: The Children’s Museum of Indianapolis)

Dracorex is a dinosaur genus of the family Pachycephalosauridae, a diverse group of small, herbivorous dinosaurs, characterized by short forelimbs, stocky and powerful hind limbs, and a short, thick neck. Their most distinguishing feature was the development of a cranial dome, which is formed by the fusion and thickening of the frontals and parietals, and in some species, peripheral bones of the skull roof. Their remains are known from the Late Cretaceous of North America, Asia, and possibly Europe. The group include Pachycephalosaurus, Stegoceras, Stygimoloch and Prenocephale

Dracorex is similar to Pachycephalosaurus and Stygimoloch, but differs from them in having a flat skull, four-spiked squamosals, enlarged supratemporal fenestrae and a skull covered entirely with dermal ossicles (knobs, rugosities, and spikes). In a paper published in 2009 , it was suggested that “Dracorex” and “Stygimoloch” represent younger ontogenetic stages of Pachycephalosaurus. 

 

References:

Bakker, R. T., Sullivan, R. M., Porter, V., Larson, P. and Saulsbury, S.J. (2006). “Dracorex hogwartsia, n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota.” in Lucas, S. G. and Sullivan, R. M., eds., Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35, pp. 331–345. 

Horner J.R. and Goodwin, M.B. (2009). “Extreme cranial ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus.” PLoS ONE, 4(10): e7626

Newt Scamander. Fantastic Beasts & Where to Find Them. New York, NY: Arthur A. Levine Books, 2001

Halloween special IV: Atlach-Nacha and the Spiders of Leng.

The male, Mongolarachne jurassica, and female, Nephila jurassica, were similar in size. Photo: Kansas University and Paul Selden

The male, Mongolarachne jurassica, and female, Nephila jurassica, were similar in size. Photo: Kansas University and Paul Selden

Clark Ashton Smith (January 13, 1893 – August 14, 1961) was an American poet, sculptor, painter and author of fantasy, horror and science fiction short stories. He was one of the big three of Weird Tales, with Robert E. Howard and H. P. Lovecraft.  His work is marked by an extraordinarily rich and ornate vocabulary, a cosmic perspective and a sardonic humor. Among his numerous contribution to the Cthulhu Mythos is Atlach-Nacha, the spider God, first introduced in “The Seven Geases” (Weird Tales, Vol. 24, No. 4, October 1934). Atlach-Nacha resembles a huge spider with an almost-human face. It dwells within a huge cavern deep beneath Mount Voormithadreth, a mountain in the now vanished kingdom of Hyperborea in the Arctic. The bloated purple spiders of Leng are thought to be its children and servitors.

Dorsal view of a near-complete specimen of Palaeocharinus tuberculatus in Windyfield chert, showing prosoma (Pr), opisthosoma (Op), and the rear three right leg appendages (RL2-4) (scale bar = 1 mm). Image credit: University of Aberdeen

Dorsal view of a near-complete specimen of Palaeocharinus tuberculatus in Windyfield chert, showing prosoma (Pr), opisthosoma (Op), and the rear three right leg appendages (RL2-4) (scale bar = 1 mm). Image credit: University of Aberdeen

From Greek mythology to African folklore, the spider has been used to represent a variety of things, and gained a reputation for causing irrational fear in humans. Among the oldest known land arthropods are Trigonotarbids, an extinct order of terrestrial arachnids related to modern day spiders. The earliest trigonotarbid known in the fossil record is from the Silurian Ludlow Bone Bed. In 1923, Stanley Hirst described five species of trigonotarbids from the Rhynie cherts under the generic names Palaeocharinoides and Palaeocharinus. These are Palaeocharinoides hornei, Palaeocharinus rhyniensis, P. scourfieldi, P.calmani and P. kidstoni.

Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet since the Devonian (>380 mya). The oldest true spiders belonged to the Mesothelae. Mongolarachne jurassica, from Daohuogo, Inner Mongolia in China, is the largest known fossil spider. Mongolarachne is remarkable for being larger than its female counterpart, Nephila jurassica, found on the same site in 2011.

 

References:

Garrison, Nicole L.; Rodriguez, Juanita; Agnarsson, Ingi; Coddington, Jonathan A.; Griswold, Charles E.; Hamilton, Christopher A.; Hedin, Marshal; Kocot, Kevin M.; Ledford, Joel M.; Bond, Jason E. (2016). “Spider phylogenomics: untangling the Spider Tree of Life”. PeerJ. 4: e1719. doi:10.7717/peerj.1719

Garwood, Russell J.; Dunlop, Jason (July 2014). “The walking dead: Blender as a tool for paleontologists with a case study on extinct arachnids”. Journal of Paleontology. Paleontological Society. 88 (4): 735–746. doi:10.1666/13-088

 

An avian vocal organ from the Mesozoic.

The Vegavis iaai specimen showing the location of the syrinx. (Adapted from Clarke et al., 2016)

The Vegavis iaai specimen showing the location of the syrinx. (Adapted from Clarke et al., 2016)

Birds originated from a theropod lineage more than 150 million years ago. Their evolutionary history is one of the most enduring and fascinating debates in paleontology. In recent years, several discovered fossils of theropods and early birds have filled the morphological, functional, and temporal gaps along the line to modern birds. The earliest diversification of extant birds (Neornithes) occurred during the Cretaceous period and after the mass extinction event at the Cretaceous-Paleogene (K-Pg) boundary, the Neoaves, the most diverse avian clade, suffered a rapid global expansion and radiation. Today, with more than 10500 living species, birds are the most species-rich class of tetrapod vertebrates.

In the mid-nineteenth century, T. H. Huxley recognized that birds were most closely related to dinosaurs. He also named the unique vocal organ in birds as the syrinx. Located at the base of a bird’s trachea, the syrinx consists of specialised cartilaginous structures, connective tissue masses, membranes and muscles. The oldest known remains of a syrinx was found within the fossilised, partial skeleton of a bird, known as Vegavis iaai, from the Late Cretaceous (66 mya) of Antarctica.

Vegavis iaai by Gabriel Lio. / Photo: CONICET

Vegavis iaai by Gabriel Lio. / Photo: CONICET

The Vegavis iaai holotype specimen from Vega Island, western Antarctica, was discovered in 1992 by a team from the Argentine Antarctic Institute, but was only described as a new species in 2005 (Clarke et al., 2005). It belonged to the clade Anseriformes, a group that includes ducks, geese and swans. Vegavis exhibits the fusion of cartilage rings and asymmetry between the left and right sides of the syrinx, that are useful for making comparisons with structural data from the present-day birds. Fused rings in Vegavis form a well-mineralized pessulus, a derived neognath bird feature, proposed to anchor enlarged vocal folds or labia. Although mineralized structures of the syrinx in Vegavis and many parts of extant Anatidae show asymmetry, Presbyornis, Chauna and Galliformes lack this feature. The absence of known tracheobronchial remains in all other Mesozoic dinosaurs may be indicative that a complex syrinx was a late arising feature in the evolution of birds, well after the origin of flight and respiratory innovations.

 

References:

Julia A. Clarke, Sankar Chatterjee, Zhiheng Li, Tobias Riede, Federico Agnolin, Franz Goller, Marcelo P. Isasi, Daniel R. Martinioni, Francisco J. Mussel and Fernando E. Novas. Fossil evidence of the avian vocal organ from the Mesozoic. Nature, 2016 DOI: 10.1038/nature19852

Clarke, J. A., C. P. Tambussi, J. I. Noriega, G. M. Erickson, and R. A. Ketcham. 2005. Definitive fossil evidence for the extant avian radiation in the Cretaceous. Nature 433:305-308.

Larsen, O. N.; Franz Goller (2002). “Direct observation of syringeal muscle function in songbirds and a parrot”. The Journal of Experimental Biology. 205 (Pt 1): 25–35.

Xing Xu, Zhonghe Zhou, Robert Dudley, Susan Mackem, Cheng-Ming Chuong, Gregory M. Erickson, David J. Varricchio, An integrative approach to understanding bird origins, Science, Vol. 346 no. 6215, DOI: 10.1126/science.1253293.

A brief history of Pterosaurs.

 

Holotype specimen of Pterodactylus antiquus,

Pterodactylus antiquus, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA (From Wikipedia Commons)

In 1784, Cosimo Alessandro Collini, a former secretary of Voltaire and curator of the natural history cabinet of Karl Theodor, Elector of Palatinate and Bavaria, published the first scientific description of a pterosaur. The specimen came from one of the main sources of such fossils, the Late Jurassic lithographic limestones of northern Bavaria, and Collini, after much deliberation, interpreted it as the skeleton of an unknown marine creature. In 1801, on the basis of Collini’s description, George Cuvier identified the mysterious animal as a flying reptile. He later coined the name “Ptero-Dactyle”. This discovery marked the beginning of pterosaur research.

Pterosaurs are an extinct monophyletic clade of ornithodiran archosauromorph reptiles from the Late Triassic to Late Cretaceous. The group achieved high levels of morphologic and taxonomic diversity during the Mesozoic, with more than 150 species recognized so far. Pterosaurs have traditionally been divided into two major groups, “rhamphorhynchoids” and “pterodactyloids”. Rhamphorhynchoids are characterized by a long tail, and short neck and metacarpus. Pterodactyloids have a much larger body size range, an elongated neck and metacarpus, and a relatively short tail. Darwinopterus from the early Late Jurassic of China appear to be a transitionary stage that partially fills the morphological gap between rhamphorhynchoids and pterodactyloids.

The fossil remains of the animal kingdom London :Whittaker, Treacher,1830. http://biodiversitylibrary.org/item/111771

The holotype specimen of Dimorphodon macronyx found by Mary Anning in 1828 (From Wikimedia Commons)

The second pterosaur to be discovered also came from the Solnhofen Limestone and was named Ornithocephalus brevirostris by Samuel Thomas von Sömmerring in 1817. The specimen was even smaller than Pterodactylus antiquus, with a wingspan of only 25 cm. On December of 1828, Mary Anning found the first pterosaur skeleton outside Germany. William Buckland made the announcement of Mary’s discovery in the Geological Society of London and named Pterodactylus macronyx in allusion to its large claws. The animal had a wingspan of around 1.4 m with an elongate tail. The specimen was twice the size of Pterodactylus antiquus. The skull of Anning’s specimen had not been discovered, but Buckland thought that the fragment of jaw in the collection of the Philpot sisters of Lyme belonged to a pterosaur. In the 1850s, another specimen was found, this time with a skull at Lyme and another skull was found later. The skulls of the Lyme Regis pterosaurs bore no resemblance to those of the Solnhofen Limestone in Germany, so Richard Owen erected the new generic name Dimorphodon (Martill, 2013).

Water colour by the Reverend G. E. Howman (From Martill 2015)

Water colour by the Reverend G. E. Howman (From Martill 2015)

In 1829 the Reverend George Howman painted the earliest restoration of a pterosaur. The watercolour also incorporates a ruined castle and a ship, but amazingly predicts aspects of the anatomy of pterosaurs not brought to light by fossils discovered until a few decades later. There’s little doubt that the watercolour by Howman was intended to represent the Pterodactylus discovered by Mary Anning. A label on the back of the work reads: ‘By the Revd G. Howman from Dr [Burckhardt’s] account of a flying dragon found at Lyme Regis supposed to be noctivagous’ . The watercolour Duria Antiqior by Henry de la Beche, also represents several pterosaurs flitting over a scene of ichthyosaur and plesiosaur, representing the Liassic Sea based on fossils found by Mary Anning.

Skull of Pteranodon sp. in the American Museum of Natural History (From Wikipedia Commons)

Skull of Pteranodon sp. in the American Museum of Natural History (From Wikipedia Commons)

In 1845, James Scott Bowerbank exhibited a portion of the snout of ‘a new and gigantic species of Pterodactyl’ at a meeting of the Geological Society of London. The specimen was named Pterodactylus giganteus. He also considered that many of the bones described as avian by Richard Owen, were most likely to be from ‘pterodactyls’.

The discovery of Pteranodon by O.C. Marsh in 1870, eclipsed previous pterosaur discoveries. Pteranodon was the first pterosaur found outside of Europe. Marsh’s discoveries were made in the Late Cretaceous Smoky Hill Chalk deposits of western Kansas. Prior to this discovery, the largest pterosaur fossils known were fragmentary remains from the Cretaceous Chalk of southern England. Edward Drinker Cope, Marsh’s rival, also unearthed several specimens of large North American pterosaur.

Quetzalcoatlus skeleton. (Image Credit: Texas Tech University)

Quetzalcoatlus skeleton. (Image Credit: Texas Tech University)

The first evidence of non-American pterosaurs that rivalled Pteranodon in size was made by C. A. Arambourg around 1940. The specimen was named Titanopteryx philidelphiae. But it was not until the 1970s, that relatively frequent discoveries of giant pterosaurs began again. In 1971,  Douglas A. Lawson, a geology graduate student from the University of Texas, found a 544-mm long humerus and other elements of a huge wing in the Maastrichtian Javelina Formation of Texas. The specimen was named Quetzalcoatlus after the Mexican deity Quetzalcoatl, who was worshipped by the Aztecs in the form of a feathered snake. In 1975, Lawson reidentified Arambourg’s pterosaur metacarpal as a cervical vertebra from a Quetzalcoatlus-like animal, and one with similar proportions to Quetzalcoatlus northropi.

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Illustration from the original serialization of The Lost World.

Jules Verne was the first to introduce Pterosaurs into popular fiction in his novel ”Journey to the Centre of the Earth”, published in France in 1874. In “The Lost World” written by Sir Arthur Conan Doyle, which appeared in The Strand Magazine from April through November of 1912, pterosaurs are central figures. At the beginning of the novel, Professor George Edward Challenger claims to have captured and subsequently lost, a living specimen in South America. After being ridiculed for years, he invites E. Malone, a reporter for the Daily Gazette, Professor Summerlee and Lord John Roxton, an adventurer who knows the Amazon to join him to a trip to South America and prove his story. Later, the crew were attacked by pterodactyls in a swamp. Doyle compares the place with one of the Seven Circles of Dante and described as followed: “The place was a rookery of pterodactyls. There were hundreds of them congregated within view. All the bottom area round the water-edge was alive with their young ones, and with hideous mothers brooding upon their leathery, yellowish eggs”. Doyle completes the scenes by describing the males: “Their huge, membranous wings were closed by folding their fore-arms, so that they sat like gigantic old women, wrapped in hideous web-coloured shawls, and with their ferocious heads protruding above them. Large and small, not less than a thousand of these filthy creatures lay in the hollow before us”.

The Lost World novel has been so immensely popular that it has had a lasting effect, and has contributed significantly to the fascination with dinosaurs and pterodactyls. In 1994, Arthurdactylus a genus of pterodactyloid pterosaur from the Lower Cretaceous  of Brazil was named in honor of Arthur Conan Doyle.

References:

Martill, D.M., 2010. The early history of pterosaur discovery in Great Britain. In: Moody, R.T.J., Buffetaut, E., Naish, D., Martill, D.M. (Eds.), Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications 343, 287–311.

Martill, D.M., Dimorphodon and the Reverend George Howman’s noctivagous flying dragon: the earliest restoration of a pterosaur in its natural habitat. Proc. Geol. Assoc. (2013), http://dx.doi.org/10.1016/j.pgeola.2013.03.003

Martill, D. M, and Pointon, Tony, Dr Arthur Conan Doyle’s contribution to the popularity of pterodactyls, Geological Society, London, Special Publications, 375, 2013, doi:10.1144/SP375.19

WITTON, M. P., 2010 Pteranodon and beyond: the history of giant pterosaurs from 1870 onwards. In: Moody, R.T.J., Buffetaut, E., Naish, D., Martill, D.M. (Eds.), Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications 343, 287–311.

P. Taquet, K. Padian, The earliest known restoration of a pterosaur and the philosophical origins of Cuvier’s Ossemens Fossiles, C. R. Palevol 3 (2004).

“Where No Dinosaur Has Gone Before”

The Starship Enterprise flies over an orange planet in 'The Man Trap,' the premiere episode of 'Star Trek,' which aired on September 8, 1966. (CBS via Getty Images)

The Starship Enterprise flies over an orange planet in ‘The Man Trap,’ the premiere episode of ‘Star Trek,’ which aired on September 8, 1966. (CBS via Getty Images)

Star Trek has been a cult phenomenon for decades. The Original Series premiered on September 8, 1966, and has spawned four successor shows starting in the 1980s and 13 feature films , comic books, novels and an animated series. Star Trek also influenced generations of viewers about advanced science and engineering. Of course, geology played an important role on the show. In the episode “That Which Survives”, we met the senior geologist D’Amato when the USS Enterprise investigates a planet similar to Earth . Unfortunately, D’Amato was soon killed by the hologram of a beautiful woman, Losira, the last survivor of a Kalandan outpost.

Lieutenant D'Amato, the senior geologist aboard the USS Enterprise serving under Captain James T. Kirk.

Lieutenant D’Amato, the senior geologist aboard the USS Enterprise serving under Captain James T. Kirk.

Every incarnation of Star Trek introduced several alien life forms, including the Gorn, a reptilian alien race, a common motif in mythology, folklore, science fiction, conspiracy theories, ufology, and cryptozoology. In the episode “Distant Origin” (Star Trek: Voyager, 1997), the Voth, an ancient civilization in the Delta Quadrant, discovered  the remains of a human Voyager crew member on the planet Hanon IV. Voth scientist Gegen believes he finally has confirmation of his “distant origin” theory. According to Gegen, the Voth actually migrated to the Delta Quadrant from an original planet far away. Later, we discovered that the Voth presumably descended from Parasaurolophus.

The episode, a metaphor for the relationship between Galileo Galilei and the Catholic Church, plays with the infamous “Dinosauroid  Hypothesis” (a.k.a. Sapient Dinosaurs). In the early 1980s, paleontologist Dale Russell, curator of vertebrate fossils at the National Museums of Canada, in Ottawa, speculates about a possible evolutionary path for Troodon, suggesting that it could have evolved into intelligent beings similar in body plan to humans. Troodon, a relatively small theropod, comparable in size to Deinonychus and Unenlagiahad a very large brain for its size, stereoscopic vision, raptorial hands and an enlarged sickle− shaped claw on the foot, indicative of a predatory lifestyle. In the novel First Frontier (Star Trek, Book 75) written by Diane Carey and Dr. James I. Kirkland, a paleontologist who discovered the famous Utahraptor, we found that the U.S.S. Enterprise is caught in an alternative reality where the Earth is a vast jungle-like paradise  ruled by the Clan Ru, an alien race, descendant of Earth’s raptor dinosaurs. The Clan Ru posses two fingers on each hand with an opposable thumb as in Russell’s model for Troodon evolution.

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References:

Russell, D. A., & Séguin, R. 1982. “Reconstruction of the small Cretaceous theropod Stenonychosaurus inequalis and a hypothetical dinosauroid.” Syllogeus 37, 1-43.

Junchang Lü; Li Xu; Yongqing Liu; Xingliao Zhang; Songhai Jia; Qiang Ji (2010). “A new troodontid (Theropoda: Troodontidae) from the Late Cretaceous of central China, and the radiation of Asian troodontids.” Acta Palaeontologica Polonica. 55 (3): 381–388. doi:10.4202/app.2009.0047.

Diane Carey, James I. Kirkland, First Frontier (Star Trek, Book 75) Paperback, August 1, 1995.