Vertebrate Zoology Exam 3 Notes

Vertebrate Zoology Exam 3 Notes - Exam #3 Notes...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Exam #3 Notes Sarcopterygian Fish (Exclusive of Tetrapods) 1) Features a) Retain lungs (mostly) b) Lateral fins supported by bony struts c) Diphycercal tail primitive feature d) Cosmoid scales i) Similar to ganoid scales because they have a bony core ii) Called cosmine iii) Thin enamel cover 2) 3 Major Lineages a) Lungfish (Dipnoi) b) Coelacanthes (Actinista) c) Rhipidistians (Rhipidistra) 3) Coelacanthes a) Until the 1930s, they were believed to be extinct near the end fo the Cretacious. b) Single living genus: Lat imeria c) Live in the deep waters of the Indian Ocean (lungs surpressed) d) Advanced ureately i) Blood feature: blood is loaded with the chemical urea ii) Heavy urea concentrat ion makes Lat imeria hyperosmotic to sea water 4) Lungfish (Dipnoans) a) Hugely diverse in Devonian (found in most water environments, many genera) b) 3 living forms i) Neoceratodus (Australian) ii) Protopterus (African) iii) Lepidosiren (S. American) c) Features i) Lungs are very important for gas exchange (Lungs are very important for gas exchange (Lepidosren: obligate air breather) ii) Upper jaw bones are fused into solid st ructures (1) While the teeth form broad plates iii) All extent forms are aquat ic, tend to prefer slugglish waters iv) All obligatorily t ropical v) Est ivat ions (1) Process used to escape dry condit ions (2) Means for surviving drought (3) An adaptat ion for dealing with severe drought (4) Pr im it ive in lung fish (lacking in Neoceratodus) (5) Two steps: (a)Bu rrow dug in the lake/river bottom (b)Lungfish wraps itsslef in a protenaceous cacoon (i) Doesnt always work 5) Rhipidist ians a) Ext inct (as fish) b) Devonian Carboniferous c) Ancestors of tetrapods d) Features i) Diagnostic bone arrangement in the limbs ii) Skull bones have very mobile st ructures (1) Kinet ic skullbones iii) Elongatd skulls iv) Retain diphycercal tail v) Labyrinthine tooth enamel vi) Pr imarily fresh water (look at diagram) Tet rapods: Overview and Origins 1) 1 st appear in the late Devonian 2) Challenges to Life on Land a) Gas exchange: delt with by retaining lungs (ancient bony fish feature) b) Dessication (no direct evolutionary response) c) Gravitational compression d) Getting food into the mouth and swallowing food (solutin: tongue) e) Food moistening (solut ion: saliva) f) Tu rn ing the head (solut ion: neck) i) Neck = a specialized part of the spinal column 3) Pandericthys a) Lacked a neck b) Dorsal, posteriong-directed eye c) Limb bone fairly conservative 4) Acanthastega a) Commonly considered the earliest known tetrapod i) Tet rapod-like limb bones ii) Neck b) Not terrest rial i) Ta il fin remnants ii) Lateral line system present (1) The ability to hear with an ent ire body....
View Full Document

Page1 / 13

Vertebrate Zoology Exam 3 Notes - Exam #3 Notes...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online