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

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

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

 

Fossilized dinosaur brain tissue identified

Computer animation of a fossilized dinosaur brain (Credit: University of Manchester)

Our knowledge of dinosaurian braincases and the structure of their endocranial cavities has a surprisingly long history. The first well-preserved braincase (NHMUK R2501) was found almost 150 years ago in the Isle of Wight and was described as probably belonging to Iguanodon. In 1897, Charles William Andrews – using the same specimen – suggested that dinosaurian brains, and in particular their lobes and surface convolutions, were not closely pressed against the cranial wall. Almost sixty years later, John Ostrom published a study on the anatomy of the hadrosaurian dinosaurs of North America and reinforced the general opinion that they had brains that were not packed tightly within the braincase. Previously, Alfred Romer observed that the interior walls of reptile braincases reflect the shape of the brain at an early state of its development. Now, a team of paleontologists from the University of Cambridge and the University of Western Australia uncovered the first fossilized brain tissue from a dinosaur.

The extraordinary specimen is likely to have belonged to a species related to Iguanodon, which lived around 133 million years ago. It was found in 2004 by fossil hunter Jamie Hiscocks, near Bexhill in Sussex. Fossilized footprints and trackways of Iguanodon-like ornithopods were found at a similar stratigraphic level.

Images of (a) the Bexhill iguanodontian natural endocast specimen and (b) a computed tomography. Scale bar: 10 mm (From Brasier et al., 2016)

The natural cranial endocast was unusually well preserved along its dorsolateral flanks, corresponding to the approximate position of the cerebellum. A scanning electron microscopy (SEM) revealed detailed structures, interpreted as meningeal fabrics, blood vessels and potentially superficial cortical tissues, which have been replaced by calcium phosphate or moulded by microcrystalline iron carbonate. The meningeal structures show similarities with those seen in crocodiles and birds. The areas occupied by the forebrain lobes and hypothalamus were well developed, so it’s reasonable to suppose that iguanodontian dinosaurs of this type had moderately complex behaviour similar to modern crocodilians.

To preserve soft tissue as phosphate is necessary a locally anoxic environment to promote bacterially mediated mineralization. Under freshwater conditions, eutrophication adds phosphate to the water column in the form of a phosphoric acid series that reduce the pH of the water, rapidly fixing soft tissues, and dissolving the surrounding mineralized tissues. As result, the soft tissues associated with the brain could have been preserved and cast prior to complete burial by sediment (Brasier et al., 2016).

References:

Martin D. Brasier et al.’ Remarkable preservation of brain tissues in an Early Cretaceous iguanodontian dinosaur.’ Earth System Evolution and Early Life: a Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications, 448. (2016). DOI: 10.1144/SP448.3
Ostrom, J.H. 1961. Cranial anatomy of the hadrosaurian dinosaurs of North America. Bulletin of the American Museum of Natural History, 122, 35–196

Forgotten women of Paleontology: The Newnham quartet.

Ethel Skeat (right) and Margaret Crosfield (middle) at Oswestry, 1908 (From Burek and Malpas, 2007)

Women have played  various and extensive roles in the history of geology. In the 18th and 19th centuries women’s access to science was limited, and science was usually a ‘hobby’ for intelligent wealthy women. They collected fossils and mineral specimens, and were allowed to attend scientific lectures, but they were barred from membership in scientific societies. It was common for male scientists to have women assistants, often their own wives and daughters. A good example of that was Mary Lyell (1808–1873), daughter of the geologist Leonard Horner and the wife of eminent geologist Charles Lyell. Unfortunately, their contribution has not been widely recognised by the public or academic researchers.

Newnham Hall was founded by Henry Sidgwick in 1875, and was the second Cambridge College to admit women after Girton College. The co-founder of the college was Millicent Garrett Fawcett, primarily known for her work as a suffragist. In 1879, Professor Charles Lapworth, the man who solved the great Cambro-Silurian controversy, encouraged a small group of women at Newnham College to investigate the Silurian and Ordovician rocks of North Wales. Those women were: Gertrude Elles, Ethel Shakespear (née Wood), Ethel Woods (née Skeat) and Margaret Chorley Crosfield.

Newnham began as a house for five students in Regent Street in Cambridge in 1871

Ethel Gertrude Skeat was born on 14 May, 1865, in Cambridge, England. She was the third daughter of Professor William Walter Skeat. In 1891, she went to Newnham College, Cambridge, at the same time as Gertrude Elles and Ethel Wood. In Newham, she also met  her life-long friend and collaborator, Margaret Crosfield. She completed the Natural Science Tripos certificate part 1, gaining a Class 1 at the age of 29, but without being awarded a degree. In 1893, she joined the Geologists’ Association (GA) and collaborated with her long-time friend, Margaret Crosfield, on their first paper on Welsh stratigraphy in the Carmarthen area, which was published in the Quarterly Journal of the Geological Society in 1896. Ethel won a Bathurst Studentship which she used to go to Munich to work with Karl Alfred von Zittel. She was the first woman to be admitted as a guest to scientific lectures at Munich University after a petition by Professor Zittel. She also collaborated with Victor Madsen on an important work on the Glacial Boulders of the Mesozoic of Denmark. In 1908, she was awarded the Murchison Fund by the Geological Society of London and became the 8^th woman to receive any kind of funding from the Geological Society . In 1911, a few months after her marriage with Henry Woods, she became a lecturer at the Cambridge Training College for Women and remained there for 2 years. She died on 26 January 1939 in Meldreth, England.

Margaret Crosfield on a Geologists’ Association field trip to Leith Hill with Professor Lapworth (From Burek and Malpas, 2007).

Margaret Chorley Crosfield was born on 7 September 1859 in Reigate, Surrey. She entered Newnham in 1879 at the age of 20 years but her studies there were interrupted by ill health. She returned to complete her studies 10 years later and with the permission of the authorities she only took geology as a subject. She joined the GA in 1892 and 17 years later she was among the first group of women to be elected Fellows of the Geological Society of London. She published three important papers. The first was on Carmarthen with Ethel Skeat that formed the basis of the geological map produced by the British Geological Survey for the area. In 1914, Margaret published with Mary Johnston a work on the Wenlock limestone of Shropshire. Later, in 1925, she published her second paper with Ethel Skeat (now Mrs. Woods) on the geology of the Silurian rocks of the Clwydian Range. She was also a great promoter of women’s suffrage and some of her field notes are written on the back of suffragette notepaper. She died October 13, 1952.

Dr Gertrude Elles (1872-1960), pioneer woman geologist (Image: Sedgwick Museum archives)

Gertrude Lilian Elles was born in Wimbledon on 8 October 1872. She attended Newnham College, Cambridge, at the age of 19 and studied under the guidance of Thomas McKenny Hughes and John Edward Marr, two of the leading geologists of the period. She travelled to Trinity College, Dublin, as one of the ‘Steamboat Women’ to receive her DSc in 1905. Elles was a field geologist, stratigrapher and palaeontologist. Her major work concerned the interpretation of graptolite zones of Lower Palaeozoic strata. Graptolites are extinct marine creatures that formed net-like colonies composed of one or more branches. In the late 1890s, she and her Newnham friend and colleague Ethel Wood began the preparation of British Graptolites (1901-1918), a monograph which was produced in parts over the next twenty years under the general editorship of  Professor Charles Lapworth. In 1919 she won the Murchison Medal and became one of the first female Fellows of the Geological Society. She had not an official university position at Cambridge until 1926 when she was appointed to a university lectureship. Ten years later, she became the first woman Reader. She died on November 18, 1960.

Ethel Wood (1871–1945).

Ethel Reader Wood was born on on 17 July 1871 at Biddenham, near Bedford. Her lifelong friendship with Gertrude Elles began in 1891 when she went up to Newnham College where she obtained a First Class degree specializing in geology. Her first work was a study of rocks in the Lake District, suggested by Professor Marr and undertaken jointly with Elles. The results were published in the Geological Magazine in 1895. A year later, she went to Birmingham University as research assistant to Charles Lapworth. Two of her own publications from this period were especially important. The first was a 1900 paper on the Ludlow formations. The second was her paper on the Tarannon series published in 1906, almost a small monograph on those beds, which made plain their stratigraphic relationship to the better-known Upper Llandovery horizon. In 1904 she won the Wollaston Fund from the Geological Society and the following year she was elected an Associate of Newnham College. She became a Fellow of the Geological Society in 1919 and the following year, shortly after the last part of the monograph came out, was awarded the Murchison Medal. Like Marie Stopes, she gained national recognition not for her geological work but for her social activities, specifically her efforts during World War I. For her public service she received an MBE in 1918 and a DBE in 1920. She died of cancer in 1946.

Thanks to the pioneer work of these women, the 20th century saw the slow but firm advance of women from the periphery of science towards the center of it.

References:

Burek, C.V., and J.A. Malpas, (2007). “Rediscovering and conserving the Lower Paleolithic ‘treasures’ of Ethel Woods (née Skeat) and Margaret Crosfield in northeast Wales.” In Cynthia V. Burek and Bettie Higgs, eds., The Role of Women in the History of Geology. London: Geological Society, Special Publications, vol. 281, pp. 203–226.

C. V. Burek (2007). The role of women in geological higher education – Bedford College, London (Catherine Raisin) and Newnham College, Cambridge, UK, Geological Society, London, Special Publications, eds Burek C. V., Higgs B. 281, pp 9–38. 

Creese, Mary R. S.; Creese, Thomas M. (2009). “British women who contributed to research in the geological sciences in the nineteenth century”. The British Journal for the History of Science. 27 (01): 23. doi:10.1017/S0007087400031654

An avian vocal organ from the Mesozoic.

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

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.

 

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 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)

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)

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)

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.

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).