So, it's transitional fossils you want, Bucko! Well, a short list is below. Google those and check back in a couple months dude
Darwinius masillae— a link between earlier primates and later ones.
Non-human primate to human
Sahelanthropus tchadensis— One of the oldest known species in the human family tree. Lived around 6.5-7 million years
ago, one of the earliest bi-pedal fossils.
Orrorin tugenensis— Over 20 fossils of the 6 million year old species have been found and show very human-like
Ardipithecus ramidus— 4.5 million year old species showing bi-pedal adaptations and opposable thumbs.
Australopithecus— a genus of bipedal apes
Kenyanthropus platyops— 3.5 million year old himinim fossil, most likely a subspecies of Australopithecus
Australopithecus sediba— advanced australopithecus showing more human features
Homo habilis— a transitional form from Australopithecus to later Homo
Homo rudolfensis— a type of Homo habilis or a different species
Homo ergaster— a form of Homo erectus or a distinct species
Homo georgicus— a form of Homo Erectus or a distinct species
Homo erectus— a transitional form from Australopithecus to later Homo (Latin for humans) species
Homo antecessor— is an extinct human species, or subspecies, dating from 1.2 million to 800,000 years ago
Homo heidelbergensis— A possible common ancestor of modern man and homo neanderthalensis
Homo neanderthalensis— They may or may not have done Humpy bumpy with modern humans.
Homo floresiensis— Extinct Homo species, living 94,000-12,000 years ago, used tools, bipedal, very human-like
Cro-magnon— considered early modern human and perhaps as smart as we are
Invertebrate to Vertebrate
Unnamed Upper (U.) Pre-Cambrian chordate — First to bear a primitive notochord; archaetypical chordate.
Pikaia gracilens— Middle (M.) Cambrian chordate with lancelet-like morphology.
Haikouella— Lower (L.) Cambrian chordate, first to bear a skull; archaetypical craniate.
Haikouichthys— L. Cambrian quasi-vertebrate, intermediate in developing a vertebral column; archaetypical vertebrate.
Conodonts— U. Cambrian to Triassic quasi-vertebrates with spinal cord; “bug-eyed lampreys”.
Myllokunmingia— L. Cambrian vertebrate with primitive spinal column; oldest true crown-group vertebrate.
Arandaspis— L. Ordovician vertebrate, armoured jawless fish (ostracoderm), oldest known vertebrate with hard parts known
from (mostly) complete fossils.
Jawless Fish to Jawed Vertebrate
Birkenia— Silurian primitive, jawless fish, a typical member of the Anaspida
Cephalaspis— Silurian armoured jawless fish, archaetypical member of the “Osteostraca,” sister group to all jawed
Shuyu— Silurian to Devonian, armoured jawless fish belonging to Galeaspida, related to Osteostraca. Internal cranial
anatomy very similar to the anatomy seen in basal jawed vertebrates. This similarity is directly implied with the translation
of its name, “Dawn Fish,” with the implication that it represents the “dawn of jawed vertebrates.”
Acanthodian to Shark
Ptomacanthus— sharklike fish, originally described as an acanthodian fish: brain anatomy demonstrates that it is an
intermediate between acanthodians and sharks.
Cladoselache— primitive/basal shark.
Tristychius— another sharklike fish.
Ctenacanthus— primitive/basal shark.
Paleospinax— sharklike jaw, primitive teeth.
Spathobatis— Ray-like fish.
Protospinax— Ancestral to both sharks and skates.
Primitive Jawed Fish to Bony Fish
Acanthodians— superficially similar to early bony fishes, and some have been identified as being the ancestors of sharks.
Palaeoniscoids— primitive bony fishes.
Canobius, Aeduella— palaeoniscoids with more advanced jaws.
Parasemionotus— combination of modern cheeks with more primitive features, like lungs
Oreochima— first teleost fish
Leptolepids— vaguely herring-like ancestors of modern teleost fish. Lung modified into swim bladder.
Amphistium and Heteronectes— percomorphs that demonstrate the transition of the eye location of flatfishes.
Fish to amphibian
Paleoniscoids— both ancestral to modern fish and land vertebrates.
Osteolepis— modified limb bones, amphibian like skull and teeth.
Kenichthys— shows the position of exhaling nostrils moving from front to fish to throat in tetrapods in its halfway point, in
Eusthenopteron, Sterropterygion— fin bones similarly structured to amphibian feet, but no toes yet, and still fishlike bodily
Panderichthys, Elpistostege— tetrapod-like bodily proportions.
Obruchevichthys— fragmented skeleton with intermediate characteristics, possible first tetrapod.
Tiktaalik— a fish with developing legs. Also appearance of ribs and neck.
Acanthostega gunnari— famous intermediate fossil. most primitive fossil that is known to be a tetrapod
Ichthyostega— like Acanthostega, another fishlike amphibian
Hynerpeton— A little more advanced then Acanthostega and Ichtyostega
Labyrinthodonts— still many fishlike features, but tailfins have disappeared
Lungfish—A fish-that has lungs.
Primitive to modern amphibians
Triadobatrachus— primitive frog
Karaurus— primitive salamander
Amphibian to reptile
Early Reptile to Turtle
Odontochelys Semitestacea— partial formation of a turtle shell, showing how the hard underbelly, or plastron, formed first.
Early reptile to diapsid (dinosaurs and modern reptiles except for turtle)
Reptile to mammal
Morganucodon— a transition between “mammal-like reptiles” and “true mammals”.
Dinosaur to bird
Allosaurus—A large therapod with a wishbone
Compsognathus—A small coeleosaur with a wishbone
Microraptor— a feathered bird with distinctly dinosaurian characteristics, such as its tail.
Xiaotingia— slightly earlier than Archaeopteryx, slightly more like a dinosaur and less like a bird
Archaeopteryx— the famous bird-with-teeth.
Columba— One of many typical modern birds
Indohyus— a vaguely chevrotain-like or raccoon-like aquatic artiodactyl ungulate with an inner ear identical to that of
Ambulocetus— an early whale that looks like a mammalian version of a crocodile
Pakicetus— an early, semi-aquatic whale, a superficially wolf-like animal believed to be a direct ancestor of modern whales.
Rhodocetus— An early whale with comparatively large hindlegs: not only represents a transition between semi-aquatic
whales, like Ambulocetus, and obligately aquatic whales, like Basilosaurus.
Basilosaurus— A large, elongated whale with vestigial hind flippers: transition from early marine whales (likeRhodocetus) to
Dorudon— A small whale with vestigial hind flippers, close relative of Basilosaurus.