Researched and Written by Leila Battison
Narrated and Edited by David Kelly
Art by Khail Kupsky
Thumbnail Art and Art by Ettore Mazza

If you like our videos, check out Leila's youtube channel:

   / @somethingincredible  

Music from Epidemic Sound and Artlist.

Image credits:

Mimoperadectes By Jorge González Horovitz I, Martin T, Bloch J, Ladevèze S, Kurz C, et al. (2009) Cranial Anatomy of the Earliest Marsupials and the Origin of Opossums. PLoS ONE 4(12): e8278. doi:10.1371/journal.pone.0008278.g006, CC BY 2.5, https://commons.wikimedia.org/w/index...

Snowball Earth Oleg Kuznetsov 3depix  http://3depix.com/, CC BYSA 4.0 https://creativecommons.org/licenses/..., via Wikimedia Commons

Cyanobacteria By CSIRO, CC BY 3.0, https://commons.wikimedia.org/w/index...

Oviraptor By Jordi Payà from Barcelona, Catalonia IMG_1215&039;Uploaded by FunkMonk, CC BYSA 2.0, https://commons.wikimedia.org/w/index...

Oviraptor skull By Jaime A. Headden  https://qilong.wordpress.com/2011/06/..., CC BY 3.0, https://commons.wikimedia.org/w/index...

Megazostrodon Reconstruction By Theklan Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Coryphodon By Jonathan Chen Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Amoeba By Cymothoa exigua Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

University of Bonn Electorial Building By I, Der Wolf im Wald, CC BYSA 2.5, https://commons.wikimedia.org/w/index...

Poppelsdorfer Alle By Itamar Medeiros Imported from 500px (archived version) by the Archive Team. (detail page), CC BYSA 3.0, https://commons.wikimedia.org/w/index...

 Chloroplasts visible in the cells of Bryum capillare By Des_Callaghan Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Liverwort_chloroplasts By Smith609 Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Oxpecker on Impala By Charles James Sharp Selfphotographed, from Sharp Photography, sharpphotography.co.uk, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Oxpecker on mammal By Prosthetic Head Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Yellowbilled oxpecker on a wildebeest By Lip Kee Yap from Singapore, Republic of Singapore Yellowbilled Oxpecker (Buphagus africanus), CC BYSA 2.0, https://commons.wikimedia.org/w/index...

A disruptively patterned whitespotted puffer being cleaned by a conspicuously coloured Hawaiian cleaner wrasse.  By Brocken Inaglory Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Remora By RyanSomma originally uploaded to Flickr as Common Remora, CC BYSA 2.0, https://commons.wikimedia.org/w/index...

Nurse shark with remoras Duncan Wright (User:Sabine's Sunbird), CC BYSA 3.0 http://creativecommons.org/licenses/b..., via Wikimedia Commons

Chlorophyll Cells By Kristian Peters Fabelfroh Selfphotographed, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Amobe By Picturepest Amöbe? 400x, 12my Fokalebene 1, CC BY 2.0, https://commons.wikimedia.org/w/index...

Chrondocyte By Robert M. Hunt Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

A fluorescent image of an endothelial cell. 
By IP69.226.103.13 Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Cellular universe By Annaleida Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Human Cheek Cells stained with Methylene Blue under 400x magnification By Fritzmann2002 Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Cèl·lules de la mucosa bucal. By Pere López Brosa, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Dolly the sheep By Paul Hudson from United Kingdom National Museum of Scotland, CC BY 2.0, https://commons.wikimedia.org/w/index...

black widow By Kenichi Ueda  https://www.inaturalist.org/photos/121, CC BY 4.0, https://commons.wikimedia.org/w/index...

Cell division by 42 By Egelberg Own work, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Spermatozoa By Vasinks Own work, CC BYSA 4.0, https://commons.wikimedia.org/w/index...

Meosis By Doc. RNDr. Josef Reischig, CSc. Author&039;s archive, CC BYSA 3.0, https://commons.wikimedia.org/w/index...

Mitochondrion By Kelvinsong; modified by Sowlos Own work based on: Mitochondrion mini.svg, CC BYSA 3.0, https://commons.wikimedia.org/w/index...