There could not have had a better paper to kick of the first content post of this blog than the present Dr. Kenneth Carpenter gave us last Sunday when redescribing "Amphicoelias" fragillimus and naming a new genus to make it separate from the type species of the genus. Not only that but he also formally publishes something many of us in the internet have been saying in the last 4 years, "A." fragillimus is a basal rebbachisaurid.
01-The Birth of Rebbamphi:
The first person to suggest "Amphicoelias" fragillimus might have been a rebbachisaurid rather than a diplodocid was Andrea Cau, Italian Theropod specialist, in his Blog in 2012 (link N°-01). He did not entered in much detail there but shows that "A." fragillimus was in a polytomy at the base of Diplodocoidea and they had similar characters regarding the neural arches and lamination of the vertebrae, so it might have been a basal rebbachisaurid. In the end he just said it was just a provocation, though if true it would be more reasonable than the diplodocid-like size estimates.
02-Popularization of Rebbamphi:
Though Cau was the first to propose such possibility the guy that actually popularized the idea of Rebbamphi was Zachary Armstrong (aka: Zach Armstrong), an independent paleoblogger, in a journal posted in his Deviant Art in March of 2014 (link N°-02). There he presents a reconstruction of a fragillimus vertebra with the unknown parts being filled by Rebbachisaurus and Limaysaurus rather than a diplodocid like Diplodocus as was usually done, and show the know bits were indeed more similar to those of rebbachisaurids than the more derived diplodocids.
In a similar way to Cau, Armstrong showed that the neural arch of "A." fragillimus is actually similar to the one of rebbachisaurids than to diplodocids, looking especially like Limaysaurus. He also notes that if it was a rebbachisaurid-like animal, we could explain the fragility of the specimen being in fact a result of the pneumaticity of the skeleton; very common on rebbachisaurids. His size estimate for the animal was around 28.6 meter long.
*Also it is very nice that Carpenter did recognize Armstrong suggested this 4 years ago.
03-Carpenter's paper:
Finally we get to Dr. Carpenter's paper, during the first part of the paper he focuses on the history of the specimen and in the latter segments (past Systematic Paleontology) he focuses on giving the species a redescription and the biogeographic and evolutionary implications for Rebbachisauridae and Diplodocoidea (if his hypothesis that "A." fragillimus actually was correct).
But the most important part is in the middle of the paper (pages 7-11) where he presents the arguments behind his hypothesis; and those were the same ones used by Cau and Armstrong:
I could not have asked for a better subject for the inauguration post of this blog; now that you are aware of this story you may give my page a try and listen to my opinions because some of us armchair/self-thought paleontologists do actually know our stuff.
Link N°-01:
https://theropoda.blogspot.com/2012/01/amphicoelias-fragillimus-e-un.htm
Link N°-02:
https://www.deviantart.com/palaeozoologist/journal/Was-Amphicoelias-a-rebbachisaur-440611550
01-The Birth of Rebbamphi:
The first person to suggest "Amphicoelias" fragillimus might have been a rebbachisaurid rather than a diplodocid was Andrea Cau, Italian Theropod specialist, in his Blog in 2012 (link N°-01). He did not entered in much detail there but shows that "A." fragillimus was in a polytomy at the base of Diplodocoidea and they had similar characters regarding the neural arches and lamination of the vertebrae, so it might have been a basal rebbachisaurid. In the end he just said it was just a provocation, though if true it would be more reasonable than the diplodocid-like size estimates.
02-Popularization of Rebbamphi:
Though Cau was the first to propose such possibility the guy that actually popularized the idea of Rebbamphi was Zachary Armstrong (aka: Zach Armstrong), an independent paleoblogger, in a journal posted in his Deviant Art in March of 2014 (link N°-02). There he presents a reconstruction of a fragillimus vertebra with the unknown parts being filled by Rebbachisaurus and Limaysaurus rather than a diplodocid like Diplodocus as was usually done, and show the know bits were indeed more similar to those of rebbachisaurids than the more derived diplodocids.
In a similar way to Cau, Armstrong showed that the neural arch of "A." fragillimus is actually similar to the one of rebbachisaurids than to diplodocids, looking especially like Limaysaurus. He also notes that if it was a rebbachisaurid-like animal, we could explain the fragility of the specimen being in fact a result of the pneumaticity of the skeleton; very common on rebbachisaurids. His size estimate for the animal was around 28.6 meter long.
*Also it is very nice that Carpenter did recognize Armstrong suggested this 4 years ago.
03-Carpenter's paper:
Finally we get to Dr. Carpenter's paper, during the first part of the paper he focuses on the history of the specimen and in the latter segments (past Systematic Paleontology) he focuses on giving the species a redescription and the biogeographic and evolutionary implications for Rebbachisauridae and Diplodocoidea (if his hypothesis that "A." fragillimus actually was correct).
But the most important part is in the middle of the paper (pages 7-11) where he presents the arguments behind his hypothesis; and those were the same ones used by Cau and Armstrong:
- Neural arch morphology
- The fragility of the specimen may be caused by the fact that rebbachisaurids have highly pneumatic skeleton.
- I honestly did not understand very well one of them, but I think it is the same thing Cau said about lamination of the vertebrae
In the end the 3 researches suggested/got to this same conclusion independently, and what is especially important (and reason why I choose this as the subject of my first post) is that Armstrong does not have an academic degree in biology/geology. However he did nailed that "A." fragillimus could have actually represented a rebbachisaurid instead of another kind of diplodocoid and used the same arguments that now were used by Carpenter to support his hypothesis.
What can we learn with this? That we cannot immediately discard anyone opinion because he/she does not have an academic degree for paleontology, the real basis of a scientific opinion is not the curriculum behind the author of it, but actually the solidness of its arguments. Finally it proves that there are many talented "armchair" paleontologists hanging around in DeviantArt, Discord or in various blogs in the internet; and it's worth at least giving a chance to their opinions as they may actually be correct.
What can we learn with this? That we cannot immediately discard anyone opinion because he/she does not have an academic degree for paleontology, the real basis of a scientific opinion is not the curriculum behind the author of it, but actually the solidness of its arguments. Finally it proves that there are many talented "armchair" paleontologists hanging around in DeviantArt, Discord or in various blogs in the internet; and it's worth at least giving a chance to their opinions as they may actually be correct.
Link N°-01:
https://theropoda.blogspot.com/2012/01/amphicoelias-fragillimus-e-un.htm
Link N°-02:
https://www.deviantart.com/palaeozoologist/journal/Was-Amphicoelias-a-rebbachisaur-440611550
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