Presentation on theme: "Vertebrate Anatomy – Unit 1"— Presentation transcript:
1Vertebrate Anatomy – Unit 1 What is a Vertebrate?Vertebrate Anatomy – Unit 1
2FIRST: A Vertebrate is an ANIMAL What is an Animal?KINGDOM Level of TaxonomyIncludes all organisms that possess the following characteristics:MulticellularHeterotrophicNo cell walls around cellsSeveral other characteristics
3SECOND: A Vertebrate is a CHORDATE What is a Chordate?PHYLUM level of TaxonomyIncludes all ANIMALS that possess the following characteristics:Dorsal Hollow Nerve CordPharyngeal Gill SlitsNotochordPost-anal TailA few chordates possess ALL these characteristics at all life stages, but most only possess all of these during EMBRYONIC stages.
4THIRD: A Vertebrate is a VERTEBRATE What is a VERTEBRATE?SUBPHYLUM level of TaxonomyA level not normally addressed in intro bio classesIncludes all CHORDATES that possess the following characteristics:A BACKBONE that protects the nerve cord and supports the body; replaces the notochordThis also generally implies the presence of a cranium (skull) to protect the brain.Some animals have ONLY the cranium, thus they are not quite true vertebrates
5TRUE or FALSE? All CHORDATES are VERTEBRATES. All VERTEBRATES are CHORDATES.
7About the Notochord In a Vertebrate Chordate, the Notochord is present only during the EMBRYONIC stages of life.The notochord is replaced by the backbone
8About the Nerve Cord Dorsal Hollow Anterior end enlarged to create the BRAIN
9Pharyngeal Gill Slits Pharynx = throat Present in embryos These slits in the throat area become the gills in fish and other vertebrates that breath waterIn mammals and other land vertebrates they become structures of the lower jaw, face and throat.
11Other Chordate Characteristics Closed circulatory systemBlood always contained in blood vesselsMuscle blocks or segments called somites in embryos
12Who are the Chordates closest relatives? The closest INVERTEBRATE relative of the chordates are the members of Phylum EchinodermataThe Sea StarsThe Sea UrchinsThe Sea CucumbersHow can this be?The embryonic development of echinoderms has a very important similarity to the embryonic development of chordates, even though the adult forms look very different.
13Echinoderms and Chordates The embryonic opening called a blastopore becomes an ANUS in both echinoderms and chordates.In all other INVERTEBRATES it becomes the MOUTH.
15Subphylum Urochordata The TunicatesAlso called Sea SquirtsThe 4 Chordate characteristics are present in the larval formThe adult looks very differentLarva are free swimming with tails, etc.Adult is sessile.
19Phylum Myxini New Phylum Once thought to be vertebrates, but they do not possess a true backbone – only a true craniumHagfish is the only memberHagfish sliming videoMore slimeMore
20Subphylum VertebrataWE are vertebrates; hence humans have studied phylum vertebrata a lot.
21When did the 1st vertebrates arise on Earth? Around 500 million years ago
22What were the first vertebrates like? The first vertebrates were DIFFERENT from vertebrates we know today.They lacked JAWS.Think lampreys which are the only vertebrates that remain today who lack jaws.Jawed vertebrates did not appear until around 400 million year agolamprey videoOne more