Aparición de los primeros Tetrápodos

• (8/1/2010) Fossil Footprints Give Land Vertebrates a Much Longer History:
  http://www.sciencedaily.com/releases/2010/01/100107114420.htm
• (7/1/2010) Tetrapod trackways from the Middle Devonian period of Poland:
  https://www.researchgate.net/publication/319645411_The_earliest_tetrapod_tracks_from_Zachelmie_Quarry_Holy_Cross_Mountains_Poland
• (6/1/2010) Oldest Land-Walker Tracks Found--Pushes Back Evolution:
  https://www.nationalgeographic.com/news/2010/1/100106-tetrapod-tracks-oldest-footprints-nature-evolution-walking-land/
• (26/7/2009) Ancient Fossils Shed Light On Anatomical Changes Accompanying Evolution Of First Land Vertebrates:
  http://www.sciencedaily.com/releases/2009/07/090706171540.htm
• (19/4/2009) From Fish To Landlubber: Fossils Suggest Earlier Land-Water Transition Of Tetrapod:
  http://www.sciencedaily.com/releases/2009/04/090417144848.htm
• (18/12/2002) From Fins to Fingers:
  https://science.sciencemag.org/content/304/5667/57.full?ijkey=oBfc15ih9p2u2&keytype=ref&siteid=sci