Question

Construct a table listing the important characteristics of Branchiostoma (Amphioxus), Petromyzon (Lamprey), Squalus (Dogfish), Perca (Perch), Necturus (Mudpuppy) and Lithobates (Bullfrog) to construct a cladogram.

PLEASE construct a cladogram with these 6 generas.  This is really important.

Also, indicate which characters might be plesiomorphic (generalized for some or all of these taxa) and which might be apomorphic (derived) for each of the taxa.

Answer 1

Branchiostoma (Amphioxus)	One of the few living genera of lancelets (order Amphioxiformes) Fossil dated back to cambrian period or precambriam
Petromyzon (Lamprey)	Ancient extant lineage of jawless fish of the order Petromyzontiformes Fossils dates back at least 360 million years ago
Squalus (Dogfish)	Squalus acanthias fossils date back to the Miocene 11 MYA
Perca (Perch)	Fossils dates back to 12,000 to 10,000 year old; end of ice ages
Necturus (Mudpuppy)	Fossils found of Paleocene and Pleistocene era
Lithobates (Bullfrog)	Fossils are known from the Pleistocene (Illinoinan–Sangamonian glacial age)

Cladogram for given generas:

Branchiostoma -Petromyzon Squalus - Perca Lithobates Necturus

CUIUdld -Amphibia FAnura Ranidae Ó-Lithobates Caudata L.Proteidae Ó-Necturus -Actinopteri Perciformes LPercidae "Perca -Chondrichthyes LSqualiformes Squalidae • Squalus Hyperoartia Petromyzontiformes Petromyzontidae -Petromyzon Leptocardii Amphioxiformes Branchiostomidae Ó-Branchiostoma

Plesiomorphic: A pineal-parapineal apparatus in Branchiostoma

Apomorphic: A caudal peduncle with lateral keels and the caudal fin is without a subterminal notch are example of apomorphic character of squalus