By José C. Cortés on @ryuukibart

Group: Neoceratosauria

Classification: Cellular Life, Archaea, Proteoarchaeota, Eukaryota, Unikota, Opisthokonta, Holozoa, Filozoa, Metazoa, Eumetazoa, Planulozoa, Bilatera, Nephrozoa, Deuterostomia, Chordata, Craniata, Vertebrata, Gnathostomata, Eugnathostomata, Teleostomi, Euteleostomi, Sarcopterygii, Rhipidistia, Tetrapodomorpha, Eotetrapodiforms, Elpistostegalia, Stegocephalia, Tetrapoda, Reptiliomorpha, Anthracosauria, Batrachosauria, Cotylosauria, Amniota, Sauropsida, Eureptilia, Romeriida, Diapsida, Neodiapsida, Sauria, Archosauromorpha, Archelosauria, Archosauriformes, Crurotarsi, Archosauria, Avemetatarsalia, Ornithodira, Dinosauromorpha, Dinosauriformes, Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Ceratosauria

Definition: The clade of the most recent common ancestor of Ceratosaurus and Carnotaurus, and all of that most recent common ancestor’s descendants. 

Organisms Within: The clades Ceratosauridae and Abelisauroidea

Time Range: Given this is another node-based clade, we can only guess at when the earliest member of this group evolved. Since earliest known Abelisauroids are from the earliest portion of the Middle Jurassic, it stands to reason that the earliest Neoceratosaur had to evolve before this; the best guess at such is shown below. 

Characteristics: This group contains all the more derived members of Ceratosauria, and they remained as weird and strangely diverse as their less derived relatives. The bulk of this group included the Abelisauroids, which ranged from the huge and tiny-armed Carnotaurus to the small and fast Noasaurids. 


Neoceratosaurs were relatively medium-sized predators or smaller during the Jurassic; however, the later Abelisaurids that would inhabit mostly the Southern Hemisphere got very large and often were at the top of the food chain in their environments. 

By Jack Wood on @thewoodparable

The beginning members of this group would probably have had some feathers, though as Abelisauroids evolved, the derived Abelisaurids primarily lost their fluffy covering. Furthermore, Ceratosaurids probably had osteoderms along their back, though this says nothing about the Noasaurid group, which were primarily small and thus probably retained their feathers. 


Biogeography: It is very uncertain where Neocreatosauria originated, given that Ceratosaurs were very widespread and Neoceratosaurs were also; early members of Abelisauroidea are not helpful, either, as they are fairly widespread. As such, it is unlikely it will ever be determined where this group first evolved. 

Posts about Ceratosauridae and Abelisauroidea to come soon.


Shout out goes to @vikingstar!

anonymous asked:

What is the problem with Linnaean classification? And what other system should be used instead?

Linnaean classification is outdated based on our current knowledge of the evolution of life. 

It is a method of classifying organisms based on traits and characteristics of them that we find important; it’s entirely subjective. 

Cladistics is the classification of organisms based on their evolutionary realtionships; which no, we don’t know exactly all the time, but we’re constantly learning more and making our picture of the evolution of life on earth more complete, making cladograms and phylogenetics more and more informative every day. 

For example, birds are in the class “Aves” and the phylum “Chordata.” We arbitrarily decided that birds are different from reptiles (”Reptilia”) because they were warm blooded and had feathers. But dinosaurs, which are in the class Reptilia, are also warm blooded and also have feathers. Also, birds evolved from dinosaurs - so they’re a group of dinosaurs - which means they’re in the class Reptilia and Aves! 

Also, Synapsids are the “ancestors” of mammals. In Linnean classification, they’re put in Reptilia. However, as far as evolution is concerned, they aren’t reptiles

Also, sponges (Phylum “Porifera”) - some of them might be more closely related to more complex animals than others -

Also, almost all protists are more closely related to fungi, animals, or plants than they are to other protists, making the kingdom “Protista” functionally useless. 

ALSO, there is a very good chance that Eukaryotes are a group of Archaeans, making the “domain of life” part of Linnaeus useless and misleading as well.


So we use cladistics, which yes, retains main of the same names as Linnean classification, but they aren’t ranked anymore, and they’re defined based on evolution rather than arbitrary traits that we have magically decided are more important than others

For example of how we define groups in cladistics is Dinosauria, which is defined as the most recent common ancestor (MRCA) of Meglosaurus and Iguanodon, and all of that MRCA’s descendants. 

Another example that shows a different way we define groups is Carnosauria. Carnosauria is defined as all Tetanurans that are more closely related to Allosaurus than to modern birds. See how this is based on something that happened in the past rather than something that we just chose?

Yeah, parts of it are arbitrary - we don’t define every cladistic grade, but that’s because it would be impossible to do so! We name the groups that are really important, and the ones that aren’t we just show using cladograms. 

For an example for how you’d list that out, let’s take the house sparrow. Yes, this is going to be a long list. Yes I’m retaining the genus/species, mostly because there isn’t anything else to use. I apologize for nothing. And you can point out the important groups in a classification list by using, say, bold type, which is what I do.

Cellular Life, Archaea, Proteoarchaeota, Eukaryota, Unikonta, Opisthokonta, Holozoa, Filozoa, Metazoa (”Animalia”), Eumetazoa, Planulozoa, Bilatera, Nephrozoa, Deuterostomia, Chordata, Craniata, Vertebrata, Gnathostomata, Eugnathostomata, Teleostomi, Euteleostomi, Sarcopterygii, Rhipidistia, Tetrapodomorpha, Eotetrapodiformes, Elpistostegalia, Stegocephalia, Tetrapoda, Reptiliomorpha, Anthracosauria,  Batrachosauria, Cotylosauria, Amniota, Sauropsida, Eureptilia, Romeriida, Diapsida, Neodiapsida, Sauria, Archosauromorpha, Archelosauria, Crocopoda, Archosauriformes, Eucrocopoda, Archosauria, Avemetatarsalia, Ornithodira, Dinosauromorpha, Dinosauriformes, DinosauriaSaurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae, Euavialae, Avebrevicauda, Pygostylia, Ornithothoraces, Euornithes, Ornithuromorpha, Ornithurae, Neornithes, Neognathae, Neoaves, Inopinaves, Telluraves, Australaves, Eufalconimorphae, Psittacopassera, Passeriformes, Passeri, Passerida, Passeroidea, Passeridae, Passer domesticus