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About Traditional Art / Professional Brian ChooMale/Australia Group :iconprehistory-alive: Prehistory-Alive
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Moythomasia lineata by Gogosardina
Moythomasia lineata
2013+15, acrylics, digital and photography

Image for = Choo, B. (2015) A new species of the Devonian actinopterygian Moythomasia from Bergisch Gladbach, Germany, and fresh observations on M. durgaringa from the Gogo Formation of Western Australia, Journal of Vertebrate Paleontology. DOI:10.1080/02724634.2015.952817

link = www.tandfonline.com/doi/full/1…

ca. 380 million years ago, Late Devonian (early Frasnian), Oberer Plattenkalk, Bergisch-Gladbach, Nordrheine-Westfalen, Germany.

In a shallow sea over what will become Germany, a 20 cm long actinopterygian (Moythomasia lineata) swims in front of a shoal of smaller cousins (Moythomasia nitida) along with a tetrapodomorph (Latvius niger) and a trio of pelagic crustaceans (Montecaris strunensis)

Moythomasia lineata = an ancient actinopterygian fish named and described in the above paper by yours truly. Based on material originally collected in the 1960s and currently house in Naturhistoriska riksmuseet, Stockholm. Known from three incomplete large adults and and least 8 small juveniles. Larger specimens (including the eventual holotype) were initially described as M. cf.striata by Jessen (1968), a scale-taxon from Wildungen while the juvies were misidentified as the contemporaneous M. nitida. When I visited the collections in 2007, I determined that what we had was a new species of Moythomasia, showing that you can make discoveries without getting your hands dirty by simply snooping around museum collections. M. lineata differs from M. nitida (plus the Aussie M. durgaringa) in have a completely linear bone and scale ornament, without the little pits you find in the other species. It's also more elongate that other completely known members of the genus. The scales of the genuine M. striata have a similar ornament to lineata but a different shape and it is not clear that they belong to Moythomasia in the first place.   

Moythomasia nitida = the most common fossil fish at Bergisch-Gladbach. Originally named by Gross in 1953, however when numerous complete specimens were described by Jessen i(1968), it was the first time such an ancient ray-finned fish had been described in such detail. 

Latvius niger = A small osteolepid tetrapodomorph.

Montecaris strunensis = a phyllocarid, malacostracan crustaceans with a bivalved carapace. Living phyllocarids (leptostracans) are less than an inch long, but Devonian archaeostracan examples could grow much bigger. Montecaris was a highly successful genus of the Middle-Late Devonian with a wide distribution (Europe, Canada, Australia), typically ranging in size from 5 - 25 cm in length (with rare examples approaching 2 feet).
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Yi qi. Dragon of the Daohugou by Gogosardina
Yi qi. Dragon of the Daohugou
2015, digital, pencils and photography 2015.

(edit 10/05/2015 = diminished the excessive wing-creasing on the foreground animal)

ca.164 million years ago, Middle-Late Jurassic boundary (Callovian-Oxfordian), Tiaojishan Formation (Daohugou Biota), Hebei, China

As dusk approaches, the bantam-sized scansoriopterygid dinosaur Yi qi begins to fastidiously preen the feathers in preparation for a twilight foraging session.

Yi qi ("strange wing" in mandarin) is one incredible animal.

The exquisite fossil holotype of Yi hails from Hebei Province, in northern China. Extensive feather impressions are preserved around most of the body. But the most remarkable things are the hands. The three digits are greatly elongated (as in other scansoriopterygids like Epidendrosaurus). But there is also an enormous prong-like structure (styliform element) sticking out of each wrist. Preserved adjacent to these are broad patches of naked skin, devoid of scales or feathers.

The most likely explanation =  The three elongated fingers and the extra bony strut supported an aerodynamic flight membrane. Yi was a theropod with draconic-wings. The first ever dinosaur in the fossil record with a membranous rather than a feathery flight apparatus. It is unclear if Yi was capable of powered flight or simply glided (the authors of the paper suspect the latter).

Yi is the latest find from the Daohugou biota, a series of mid-Jurassic sites in Hebei, Liaoning and Inner Mongolia with identical super-preservation as the more famous Jehol biota of Cretaceous Liaoning. The discovery of this fauna destroyed the so-called temporal paradox (an objection to the dino-to-bird hypothesis), based on the supposed absence of bird-like dinosaurs before the traditional "first bird" Archaeopteryx. The Daohugou represents a community of feathered dinosaurs over 10 million years older than Archie.  

 Yi shared it's world with a host gliding and flying vertebrates = avialian dinosaurs (Anchiornis, Xiaotingia), pterosaurs (Darwinopterus, Jeholopterus) and gliding mammals (Volaticotherium). Vertebrate evolution seemed to have been cashing in on the flight-craze during the Jurassic of China, with numerous clades independently putting representatives in the air.

Ultimately Yi demonstrates that the transition from dinosaur-to-bird was not straightforward. Aerial adaptations evolved multiple times among the maniraptorans with a great deal of early innovation in flight. Yi's strange wing did not lead to birds, it was happily doing it's own thing.

Note that the colouration is based on taking actual fossil melanosome data at face value. According to personal communications with Xu Xing, Yi probably had very dark feathers over the head and a more neutral colouration over the rest of the body.

REFERENCE
www.nature.com/nature/journal/…

  • Xing Xu, Xiaoting Zheng, Corwin Sullivan, Xiaoli Wang, Lida Xing, Yan Wang, Xiaomei Zhang, Jingmai K. O’Connor, Fucheng Zhang & Yanhong Pan. 2015. A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings. Nature doi:10.1038/nature14423


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We made this holoscape with pics we downloaded off Google images - spared no expense.

scontent-b-sjc.xx.fbcdn.net/hp…
Microbrachius dicki = Sex in the Devonian by Gogosardina
Microbrachius dicki = Sex in the Devonian
2014, acrylics on paper, digital and photography

Image for = John A. Long, Elga Mark-Kurik, Zerina Johanson, Michael S. Y. Lee, Gavin C. Young, Zhu Min,  Per E. Ahlberg, Michael Newman, Roger Jones, Jan den Blaauwen, Brian Choo & Kate Trinajstic (2014) Copulation in antiarch placoderms and the origin of gnathostome internal fertilization. Nature DOI:doi:10.1038/nature13825

www.nature.com/nature/journal/…


ca.385 million years ago, Middle Devonian (Givetian), Eday Flags, Orkney Islands, Scotland

     In a freshwater stream feeding into Lake Orcadie in equatorial Euramerica. With amorous rivals in pursuit, a male Microbrachius dicki* sweeps a receptive female away from the pack. Swimming side by side, their pectoral fins firmly interlocked with one another, the male inserts one of his enormous claspers into the female’s cloaca where paired genital plates lined with sharp hooks lock the bony phallus in place as sperm is transferred. 

     Reproduction in jawed vertebrates (gnathostomes) involves either external or internal fertilization. It has commonly been argued that internal fertilization can evolve from external, but not the reverse. However the fossil record has thrown multiple spanners into the works.
   
     Placoderms are an extinct group of armoured fishes that are widely resolved as a paraphyletic grade of basal gnathostomes (ie. All modern jawed vertebrates evolved from placoderms). Paired claspers have been found in advanced placoderms (arthrodires and ptyctodonts), suggesting that copulation might actually be the primitive state for Gnathostomata. However, without data on the reproduction of more primitive forms, it could be argued that these were specialized features of certain placoderm subgroups. 

   Now we have discovered that antiarchs, the most primitive jawed vertebrates in the fossil record, engaged in penetrative copulation. Key to this discovery is little Microbrachius, a small Middle Devonian antiarch (about the size and shape of a modern Corydoras catfish) originally described back in 1886 and known material from Scotland, Estonia and China. Numerous newly discovered specimens from the Orkney Islands have revealed that mature males bore proportionally enormous bony claspers.

   These were serious and brutal-looking man-tools, the ventral surface consisting of a slender trunk extending from the rear of the body armour, bearing transverse ribs covered in small knobs, followed by a section bearing whopping great spikes and finally a huge blade like lateral prong for cloacal insertion. The dorsal surface was smooth, bearing a prominent sperm-channel that was probably covered in soft tissue in life. The female had some impressive genital gear as well – a pair of flat bony plates flanking her cloaca with rows of tiny hooks on the dorsal surface. Female genital plates have also been identified in the antiarchs Pterichthyodes and Bothriolepis (male claspers are so far only known from Microbrachius).

   This strongly infers that copulation first appeared very deep in the history of jawed vertebrates. We have compelling evidence that internal fertilization is the default setting for the Gnathostomata and thus spawning (shedding large quantities of eggs and sperm into the surrounding water, as practiced by most living fish and frogs), despite long being considered a "primitive" feature, is in fact a derived state in jawed vertebrates. 

*Yes, Traquair really did name it dicki roughly 1.3 centuries before we discovered it had giant bony male intromittant organs. Robert Dick was a 19th century Scottish fossil hunter who provided the first specimens of this fish.




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Penetrative copulation is the default setting for the Gnathostomata!

Paper = www.nature.com/nature/journal/…
Summary = www.nature.com/news/fossils-re… 
(Note that on the simplified cladogram, the Chondrichthyes branch is mislabelled as Placodermi - and they've credited me as "David Choo")
We made this holoscape with pics we downloaded off Google images - spared no expense.

scontent-b-sjc.xx.fbcdn.net/hp…

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Gogosardina
Brian Choo
Artist | Professional | Traditional Art
Australia
An Australian vertebrate palaeontologist. I mainly work on Silurian-Devonian fishes, especially basal actinopterygians.
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:iconanimalistic-artworks:
Animalistic-Artworks Featured By Owner Edited Aug 21, 2015  Hobbyist General Artist
Hey mate,
You have some amazing artwork, and i think its great that a fellow australian such as yourself is doing some fantastic recreations of some amazing prehistoric fauna. Keep up the amazing work! I cant wait to see more of your stuff in the future :)

-Liam
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:icongogosardina:
Gogosardina Featured By Owner 3 days ago  Professional Traditional Artist
Thanks for your kind words. Have a couple of pieces accompanying upcoming palaeo-publications, but will have to wait till those respective papers come out. 
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:iconmanuelsaurus:
Manuelsaurus Featured By Owner Edited Aug 12, 2015  Professional Digital Artist
You have a great gallery , I like it
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:icontraheripteryx:
Traheripteryx Featured By Owner Jan 7, 2015  Hobbyist General Artist
Buuuuriiiiaaaaaaan! Why wasn't I watchin' you earlier? :D
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:icongogosardina:
Gogosardina Featured By Owner Nov 26, 2014  Professional Traditional Artist
Thanks for the birthday wishes guys!
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