Classifications made easy

So before I start bombarding you with big words like Phylum and Eukaryote, let me explain all those lovely words for you.


Domain: There are three domains; Archaea, Bacteria and Eukarya. Archaea and Bacteria are single-celled organisms called ‘prokaryotes’ but are also referred to as ‘prokaryotic microorganisms’, these fellas’ have no nucleus (it’s effectively the brain of a cell). All multi-cellular organisms (every living thing on the planet that isn’t a prokaryote) have a nucleus in each cell and are called ‘eukaryotes’ or ‘eukaryotic organisms’.

Kingdom: There are six kingdoms in all, Animalia, Plantae, Fungi, Protista, Archaea/Archaeabacteria and Bacteria/Eubacteria. There are also other kingdom systems that involve there being five, seven or eight kingdoms.

Phylum: There are numerous phyla under each kingdom, but there are way too many to name now.

Class: Class falls under phylum but comes in above order.

Order: Yet another classification, there will be quite a few of these where I won’t give much of an explanation because it just gets more and more particular from here on out.


Genus: This is part of the scientific name. ‘Tyrannosaurus rex’ is a good example, ‘Tyrannosaurus’ is the genus.

Species: The second part of the scientific name. In the above example, the species name would be ‘rex’.

Subspecies: Here’s one you’ll come across often in palaeontology. This is an extra classification that we sometimes use when two members of a species appear to be the same but are slightly different, and these differences cannot be explained away by difference in gender. Because sometimes we just need to be that much more specific.



Now, with dinosaurs, it gets a lot more complicated.

Please note: I don’t expect you to read this entire post, especially everything after here, the layout gets a bit complicated because I’m unable to do a proper family tree here. You need only look up ‘Dinosaur family tree’ online to see what I’m talking about, but I’ll write the rest of this for those who are interested.


Dinosauria: a ruling of reptiles characterized by the number of bones in the skull, the presence of a flange on the upper arm bone that clearly held powerful muscles, three or fewer finger bones in the fourth finger (if a fourth finger is present), three or more vertebrae (spinal bones) that are fixed to the hip bone, a hole rather than a socket in the hip (where the leg would attach), a ball-like head on the thigh bone and a strong joint between the foot bones and the bones of the hind leg.

Under dinosauria there are two main groups; Saurischia (lizard-hipped) and Ornithischia (bird-hipped). Under each of these groups there are numerous more, and even more under those, with more under those and so on, but it can be narrowed down to 59 groups (not including Saurischia and Ornithischia).


Under Saurischia we have: Sauropodomorpha (long-necked, plant-eaters, lizard-like feet) and Theropoda (bipedal/two-legged, meat-eaters).

Sauropodomorpha includes – Sauropoda (long-necked, elephantine plant-eaters) and Prosauropoda (primitive long-necked, plant-eaters).

Sauropods include – Vulcanodontidae, Macronaria (under which Titanosauria falls), Diplodocidae, Euhelopodidae, Dicraeosauridae and Cetiosauridae.

Prosauropods include – Massospondylidae, Plateosauridae, Melanorosauridae and Anchisauridae.


Under Theropoda we have: Herrerasauridae, Coelophysoidea, Neoceratosauria (under which you find Abelisauria) and Tetanurae.

Tetanurae includes Coelurosauria (which includes Compsognathidae, Therizinosauria, Troodontidae, Ornithomimosauria, Oviraptorosauria, Alvarezsauria, Dienonychosauria and Tyrannosauroidea), Carnosauria (under which Allosauridae fall) and Spinosauria.


Now for the Ornithischia: which includes Ornithopoda, Fabrosauridae, Thyreophora, Heterodontosauridae and Marginocephalia.

Under Ornithopoda you find Iguanodontidae (which includes Hadrosauridea) and Hypsilophodontidae.

Thyreophora includes Ankylosauria (under which Nodosauridae and Ankylosauridae fall) and Stegosauria.

Marginocephalia Includes Pachycephalosauria (under which Pachycephalosaurini falls) and Ceratopsia (under which Neoceratopsia falls).

Hadrosauridea includes Lambeosaurinae and Hadrosaurinae (under which falls Edmontosaurini, Maiasaurini, Saurolophini and Hadrosaurini).

Ankylosauridae includes Polacanthidae and Ankylosaurinae.

Neoceratopsia includes Ceratopsidae (under which Centrosaurinae and Ceratopsinae fall; Chasmosaurini falls under Ceratopsinae.


That is all 59 groups, I would give details on each one now but this post is already quite long and complicated, I’ll do that in another post, I’ll put the link up here when it’s done.



Image credit: NTamura


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