Episode 456: The oldest diplodocoid and a brand new Egyptian titanosaur

Episode 456: The oldest diplodocoid and a brand new Egyptian titanosaur. Tharosaurus, a dicraeosaurid like Amargasaurus, is the oldest diplodocoid ever discovered; The brand new titanosaur, Igai, was once described from Egypt; and we discover how cupboards of interest have been the unique herbal historical past museums

Information:

There’s a brand new titanosaur, Igai semkhu supply
There’s a brand new dicraeosaurid sauropod, Tharosaurus indicus supply
The Ubirajara fossil was once formally returned to Brazil in June supply
Gavin Leng, a fossil hunter recognized for discoveries similar to Eotyrannus, just lately kicked the bucket supply
When you’re in London, take a look at the Brick Dinos show off on the Horniman Museum & Gardens supply

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The dinosaur of the day: Megapnosaurus

Additionally comprises Syntarsus and to a point Coelophysis
Discussed Megapnosaurus/Syntarsus in short in episode 426 (there’s a couple of them on show in a diorama on the Herbal Historical past Museum of Zimbabwe)
Coelophysid theropod that lived within the Early Jurassic in what’s now Africa and most likely the U.S.
Gave the look of Coelophysis, had an extended tail, walked on two legs, had brief palms, and an extended face
Equivalent in dimension and form to Coelophysis
Small to medium sized
Estimated to develop as much as 7.2 feet (2.2 m) lengthy and weigh as much as 29 lb (13 kg)
Calmly constructed and speedy
Had a big mind hollow space, so almost definitely clever particularly in comparison to different dinosaurs
In accordance with enlargement rings, lived on moderate seven years
Could have been nocturnal, in line with scleral rings taking a look very similar to fashionable nocturnal birds
Had a “vulnerable joint” within the jaw bones, which gave it a hooked premaxillary jaw (tip of the snout)
Speculation then that it was once a scavenger (couldn’t cross after reside prey)
Identify continues to be debated, as Megapnosaurus, Coelophysis or a brand new genera
Genus identify Megapnosaurus manner “giant lifeless lizard”
Two species? Megapnosaurus rhodesiensis and Megapnosaurus kayentakatae
Some paleontologists imagine Megapnosaurus to be synonymous with Coelophysis, however that is nonetheless being debated
Get started with Megapnosaurus rhodesiensis
Megapnosaurus rhodesiensis discovered within the Elliot Formation in South Africa and the Woodland Sandstone Formation in Rhodesia (now referred to as Zimbabwe)
Megapnosaurus rhodesiensis estimated to be as much as 7.2 feet (2.2 m) lengthy and weigh as much as 29 lb (13 kg)
Described as lean and lengthy, with an s-shaped neck, lengthy legs that gave the impression of legs of birds just like the secretary hen (which seems find it irresistible’s strolling on stilts)
Had shorter palms, with 4 arms on every hand, and an extended tail
No proof it had feathers, however incessantly portrayed that method, as it seemed so bird-like
Fossils first present in 1963
Holotype comprises maximum of a smartly preserved skeleton (handiest lacking cranium and neck vertebrae)
Extra fragments additionally discovered
A number of specimens present in 1985 in South Africa (Elliot Formation), and 26 specimens gathered in Zimbabwe (Woodland Sandstone Formation) in 1963, 1968, and 1972
Elliot Formation almost definitely an historic flood undeniable. Different dinosaurs that lived round the similar time and position come with the sauropodomorphs Massospondylus and Ignavusaurus, additionally ornithischians like Lesothosaurus and Heterodontosaurus
Woodland Sandstone Formation had crocodiles, Massospondylus and indeterminate prosauropods
In 1972, Raath discovered loads of bones from a minimum of 26 folks from other enlargement levels (integrated skulls and neck vertebrae, in addition to intestine contents)
Raath described the fossils in his thesis in 1977 (fossils from that locality now on the Queen Victoria Museum in Australia)
Healed fractures of the leg and ft present in Megapnosaurus rhodesiensis, and one specimen had indicators within the sacral rib of fluctuating asymmetry, that could be from dwelling in disturbing stipulations
Imaginable they hunted in packs
Imaginable sexual dimorphism, in line with some folks being tough with huge limbs and big muscle attachments in comparison to extra gracile folks which can be an identical in dimension (and adults)
Loads of variable enlargement, with some folks being higher however more youthful/extra immature than smaller, mature adults
Variable enlargement most probably commonplace in previous dinosaurs however later misplaced (birds don’t do it), and will have helped early dinosaurs adapt to harsh environments
At first named Syntarsus rhodesiensis by means of Michael Raath in 1969 in line with the Zimbabwe (Rhodesia) fossils
However in 2001, discovered there was once a beetle named Syntarsus asperulus
Ivie and others renamed Syntarsus rhodesiensis to Megapnosaurus in 2001
Some controversy right here (gets into)
In 2001, Michael Ivie and others named Megapnosaurus and blended Megapnosaurus rhodesiensis (named by means of Raath in 1969) and Megapnosaurus kayentakatae (named by means of Rowe in 1989)
Syntarsus asperulus was once a beetle, named in 1869 by means of Fairmaire (regardless that two of the authors, together with Ivie made it a junior synonym of Cerchanotus in 1990—however nonetheless, identify were already used)
Consistent with Ivie and others: “This flip of occasions calls for a brand new identify, and even supposing S. rhodesiensis is described within the duvet of the 1996 quantity 3 of the magazine SYTNTARSUS as “a small carnivorous dinosaur,” and even supposing as excellent and dependable phylogeneticists, we remember that it was once no longer in point of fact at the lizard lineage, on the scale of an entomologist, it looks as if a large lifeless lizard. So, in what could be the primary identify for a dinosaur each and every proposed in an entomological magazine, we advise the substitute identify Megapnosaurus”
“[…] this moniker turns out extremely suitable for this animal”
Debates on whether or not to lump Megapnosaurus into Coelophysis (and make Megapnosaurus rhodesiensis a junior synonym, to grow to be Coelophysis rhodesiensis)
Gregory Paul, Michael Raath, and others agree
Mentioned Coelophysis in episode 204
A pair research in 2018, by means of Barta and others and by means of Christopher Griffin, discovered sufficient variations to stay them separate
Some examples: Megapnosaurus rhodesiensis doesn’t have a 5th hand bone (metacarpal) and Coelophysis bauri does
Additionally variations in scars, grooves, and depressions at the humerus and femur (arm and leg bones)
Now directly to Megapnosaurus kayentakatae
In 1989, Timothy Rowe described a 2d species of “Syntarsus”, as Syntarsus kayentakatae, in line with a cranium and portions of a skeleton
Fossils discovered within the Kayenta Formation in Arizona, U.S. (Early Jurassic)
Kayenta Formation had rivers, and wet summers and dry winters
Different dinosaurs from the Kayenta Formation come with theropods like Dilophosaurus and Kayentavenator (which was once at the start considered Syntarsus kayentakatae/Megapnosaurus kayentakatae—however there are sufficient variations to be separate), the “Shake-N-Bake” theropod, an undescribed coelophysoid recognized from a partial skeleton present in 1978 (a whole lot of small bones cemented in combination in a dense matrix since the fossils had washed down in combination), sauropodomorphs like Sarahsaurus and Anchisaurus, heterodontosaurs, and armored dinos like Scelidosaurus and Scutellosaurus
Different animals that lived round the similar time and position come with sharks, fish, frogs, turtles, lizards, pterosaurs, mammals, crocodylomorphs, mussels, and snails
Discovered a minimum of 16 folks of Syntarsus kayentakatae (fragmentary stays)
Fossils discovered between 1977 and 1979
Kind specimen of Syntarsus kayentakatae is an absolutely mature, tough grownup
Holotype of Syntarsus kayentakatae was once distorted (most commonly left facet preserved, as it rested on left facet and was once in part buried, however proper facet together with the cranium was once uncovered to water currents)
Species identify refers to Dr. Kathleen Smith, who has the nickname “Kayenta Kay” on account of her paintings within the Kayenta Formation, which contains discovering the kind specimen of Megapnosaurus kayentakatae
Megapnosaurus kayentakatae estimated to be as much as 8.2 feet (2.5 m) lengthy and weigh as much as 66 lb (30 kg)
One giant distinction between Megapnosaurus rhodesiensis and Megapnosaurus kayentakatae is that Megapnosaurus kayentakatae had two small crests on its head (very similar to Dilophosaurus however smaller)
Whether or not to make use of the identify Megapnosaurus or Syntarsus relies on who you ask
In 2000, Alex Downs when compared Coelophysis bauri and Syntarsus rhodesiensis and located them to be so an identical that Syntarsus was once a junior synonym to Coelophysis (handiest had minor main points within the neck period and different small variations)
In 2004 Anthea Bristowe and Michael Raath synonymized Coelophysis and Syntarsus as smartly, in line with paintings on a in part disarticulated cranium of a juvenile Syntarsus specimen
Stated “that the just lately proposed facetious substitute identify for Syntarsus (Megapnosaurus) will have to no longer stand”
Discovered handiest minor variations and stated which may be as a result of they lived at other occasions (Coelophysis in Overdue Triassic and Syntarsus in Early Jurassic)
In 2017, Daniel Barta and others discovered variations within the arms of Coelophysis bauri and Megapnosaurus rhodesiensis (5th metacarpal)
In 2018 Christopher Griffin discovered Megapnosaurus to be legitimate (sufficient variations between the 2, together with that there have been some characters that numerous as Megapnosaurus grew that weren’t present in Coelophysis, like scar at the humerus, and depressions at the femur)
Even though, did so many of the options that modified whilst rising (all over ontogeny) have been the similar, and so they have been an identical in dimension as soon as absolutely grown
In 2020 Adam Marsh and Timothy Rowe stored the identify Syntarsus rhodesiensis as a substitute of the use of Megapnosaurus or Coelophysis “since the systematic relationships of those animals inside of Coelophysoidea is in flux”
In 2021 Ezcurra and others discovered that Syntarsus kayentakatae was once no longer carefully associated with Coelophysis bauri or Megapnosaurus rhodesiensis
In 2022 Skye McDavid and Jeb Bugos discovered Megapnosaurus rhodesiensis to be the legitimate identify
Controversy at the identify exchange to Megapnosaurus and whether or not the way it was once modified was once legitimate (some resources stated whether or not it was once ethically carried out)
Consistent with McDavid and Bugos, “If a taxonomic identify is invalid (preoccupied or incorrectly formulated), then it is regarded as moral to touch its unique describer or describers to tell them of the issue in order that they are able to right kind their very own error. If the unique describer or describers are unreachable (as an example if they’re deceased or don’t reply to correspondence) then the one who learns of the mistake will normally post a correction. Ivie tried to touch Raath however by no means gained a answer. He and coauthors proceeded with newsletter of the substitute identify after two years, and after being (incorrectly) informed by means of dinosaur paleontologist John “Jack” Horner that Raath was once deceased. (Michael Ivie, pers. comm.)”
Additionally stated, “The genus Megapnosaurus is right here thought to be to be most probably distinct from Coelophysis, however short of additional analysis”
Discovered Megapnosaurus rhodesiensis to be right kind, for now, however stated it may be able to be a junior synonym and “utilization of the identify Megapnosaurus rhodesiensis is beneficial. Utilization of the identify Coelophysis rhodesiensis is neither beneficial nor discouraged. Utilization of the identify Syntarsus rhodesiensis is discouraged.”
Additionally discovered that Syntarsus kayentakatae is possibly its personal genus, and suggest or not it’s provisionally known as ‘Megapnosaurus’ kayentakatae, “with citation marks indicating a problematic genus project, till a brand new genus is officially described for this species”
Different fossils discovered that can be Megapnosaurus or was Megapnosaurus/Syntarsus
Darlington Munyikwa and Michael Raath described a part of a Megapnosaurus/Syntarsus snout discovered within the Elliot Formation in South Africa (this is referred to now as Dracovenator)
A number of coelophysoid bones present in Mexico from the Early Jurassic have been described as “Syntarsus” “mexicanum” however they weren’t correctly described and are almost definitely from an indeterminate coelophysoid
Scientists referred a theropod specimen from Wales to Syntarsus sp. However in 2021 that was once later named Pendraig (mentioned in ep 360)
In 2004, Randall Irmis reported fossils of Megapnosaurus present in Lufeng Formation, China, Early Jurassic (two specimens discovered). Would imply Megapnosaurus was once additionally in Asia

A laugh Reality:

Dicraeosaurids aren’t distinctive for his or her bifurcated neural spines (like the ones on Amargasaurus), even we have now them!

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