Editing 1211: Birds and Dinosaurs

{{comic
| number    = 1211
| date      = May 13, 2013
| title     = Birds and Dinosaurs
| image     = birds and dinosaurs.png
| titletext = Sure, T. rex is closer in height to Stegosaurus than a sparrow. But that doesn't tell you much; 'Dinosaur Comics' author Ryan North is closer in height to certain dinosaurs than to the average human.
}}

==Explanation==
At the time the comic was released {{w|bird}}s were commonly considered to be a separate {{w|class (biology)|class}} of {{w|tetrapods}}. However, this classification is false according to {{w|phylogenetic taxonomy}}. Taking into account that birds developed around {{w|Late Jurassic|150 million years ago}} out of small {{w|theropod}} dinosaurs, birds along with crocodiles are indeed the remaining representatives of the {{w|Archosaur|archosaur clade}}. This premise appeared also in comic [[867: Herpetology]].

This relation between birds and dinosaurs is depicted in the comic in a {{w|cladogram}} which shows that ''{{w|Tyrannosaurus rex}}'' is more closely related to the common {{w|sparrow}} than to ''{{w|Stegosaurus}}''. Not only do the former share a phylogenetic branch, but ''T. rex'' also lived around 80 million years ''after'' ''Stegosaurus''. The concurrence of both species in popular culture is a widespread error. ''T. rex'' is also much more alike to modern birds than to other dinosaurs in terms of anatomy. This relationship was pointed out on the [http://www.sciencemag.org/content/340/6133/690 Science] journal the week of the comic.

The comic draws the conclusion that if birds must in fact be considered modern dinosaurs, the hunting practice of birds of prey (specifically, the {{w|peregrine falcon}}) is consequently a dinosaur fight. For an inveterate dinosaur aficionado like [[Randall]], this fact must make the modern world much more attractive.

The line "This is a good world." could also possibly refer to a [http://www.youtube.com/watch?v=znxFrgql5dc famous scene] from the {{w|Serenity (Firefly episode)|pilot episode}} of the television series ''{{w|Firefly (TV series)|Firefly}}'' featuring two plastic dinosaurs in a somewhat philosophic dialogue. Randall is known to be a {{w|Browncoat|fan of the series}}.

The title text is a sidesweep to the webcomic ''[http://www.qwantz.com Dinosaur Comics]'' drawn by {{w|Ryan North}}, who stands 6'6.5" (199&nbsp;cm) tall. At that page the title text of the comic [http://www.qwantz.com/index.php?comic=2420 strip] from the same day refers to Randall and ''[[xkcd]]''.

The conclusion of this comic is referenced in the title text of the last image in the [http://what-if.xkcd.com/101/ Plastic Dinosaurs] What if?

==Transcript==
:By any reasonable definition, ''T. rex'' is more closely related to sparrows than to ''Stegosaurus''.
:[Diagram showing that ''Stegosaurus'' came earlier than ''T. rex'', along with it showing that ''T. rex'' came closer in time to sparrows. Evaluation criteria "separation by time", "phylogenetic distance" and "physical similarity" are highlighted in red.]
:Birds aren't ''descended'' from dinosaurs, they ''are'' dinosaurs.
:Which means that the fastest animal alive today is a small carnivorous dinosaur, ''Falco peregrinus''.
:[A picture of two birds is shown, one large and one small.]
:It preys mainly on other dinosaurs, which it strikes and kills in midair with its claws.
:[In red:] This is a good world.

{{comic discussion}}
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