This document discusses several different fossils. It describes Pteranodon as a large flying reptile that lived in North America during the late Cretaceous period. It was the first pterosaur found outside of Europe. The document also summarizes Archaeopteryx as a small bird-like dinosaur that lived around 150 million years ago in Europe and had features of both birds and small Mesozoic dinosaurs. Additionally, it provides brief overviews of ammonites, fossil fish, Physa princepii snails, and Ostrea sculpturata oysters.

1. Dr. Nirbhay Sudhir Pimple
Department of Zoology
Abasaheb Garware College
Karve road Pune-4.

2. Pteranodon

3. Pteranodon
 Pteranodon ((/tɪˈrænədɒn/; from Greek πτερόν (pteron, "wing") and ἀνόδων
(anodon, "toothless")) is a genus of pterosaur that included some of the
largest known flying reptiles, with wingspans over 7 meters (23 feet).
 They lived during the late Cretaceous geological period of North
America in present-day Kansas, Alabama, Nebraska, Wyoming, and South
Dakota.
 More fossil specimens of Pteranodon have been found than any other
pterosaur, with about 1,200 specimens known to science, many of them well
preserved with nearly complete skulls and articulated skeletons.
 It was an important part of the animal community in the Western Interior
Seaway.
 Pteranodon was a pterosaur, meaning that it is not a dinosaur. By definition,
all dinosaurs belong to one of the two groups within Dinosauria,
i.e. Saurischia or Ornithischia.
 As such, this excludes pterosaurs. Nonetheless, Pteranodon is frequently
featured in dinosaur media and are strongly associated with dinosaurs by the
general public.
 While not dinosaurs, pterosaurs such as Pteranodon form a clade closely
related to dinosaurs as both fall within the clade Avemetatarsalia.

4.  Pteranodon was the first pterosaur found outside of Europe. Its fossils first were
found by Othniel Charles Marsh in 1870, in the Late Cretaceous Smoky Hill
Chalk deposits of western Kansas.
 These chalk beds were deposited at the bottom of what was once the Western
Interior Seaway, a large shallow sea over what now is the midsection of the North
American continent.
 These first specimens, YPM 1160 and YPM 1161, consisted of partial wing bones,
as well as a tooth from the prehistoric fish Xiphactinus, which Marsh mistakenly
believed to belong to this new pterosaur (all known pterosaurs up to that point had
teeth).
 In 1871, Marsh named the find "Pterodactylus oweni", assigning it to the well-
known (but much smaller) European genus Pterodactylus. Marsh also collected
more wing bones of the large pterosaur in 1871.
 Realizing that the name he had chosen had already been used for Harry Seeley's
European pterosaur species Pterodactylus oweni in 1864, Marsh re-named his giant
North American pterosaur Pterodactylus occidentalis, meaning "Western wing
finger," in his 1872 description of the new specimen.
 He also named two additional species, based on size differences: Pterodactylus
ingens (the largest specimen so far), and Pterodactylus velox (the smallest)

5. Archaeopteryx

6. Archaeopteryx
 Archaeopteryx (/ˌɑːrkiːˈɒptərɪks/ "old wing"),
sometimes referred to by its German
name, Urvogel ("original bird" or "first bird"), is
a genus of bird-like dinosaurs.
 The name derives from the ancient
Greek ἀρχαῖος (archaīos), meaning "ancient",
and πτέρυξ (ptéryx), meaning "feather" or "wing".
 Between the late 19th century and the early 21st
century, Archaeopteryx was generally accepted
by palaeontologists and popular reference books as the
oldest known bird (member of the group Avialae).


7.  Archaeopteryx lived in the Late Jurassic around 150 million
years ago, in what is now southern Germany, and
also Portugal, during a time when Europe was an archipelago
of islands in a shallow warm tropical sea, much closer to
the equator than it is now.
 The largest species of Archaeopteryx could grow to about
0.5 m (1 ft 8 in) in length. Despite their small size, broad
wings, and inferred ability to fly or glide.
 Archaeopteryx had more in common with other
small Mesozoic dinosaurs than with modern birds.
 In particular, they shared the following features with
the dromaeosaurids and troodontids: jaws with sharp teeth,
three fingers with claws, a long bony tail, hyperextensible
second toes ("killing claw"), feathers (which also
suggest warm-bloodedness), and various features of
the skeleton.

8. Ammonite

9. Ammonite
 Their widely-known fossils show a ribbed spiral-form
shell, in the end compartment of which lived the
tentacled animal.
 These creatures lived in the seas from at least 400 to 65
million years ago.
 Their nearest living relatives are
the octopus, squid, cuttlefish and Nautilus.
 Ammonites first appeared in the early Devonian period.
 They evolved from a small, straight shelled Bactridian,
which was an early Nautiloid.

10.  They quickly evolved into a variety of shapes and sizes,
including some shaped like hairpins. During their evolution the
ammonites faced no fewer than four catastrophic events that
would eventually lead to their extinction.
 The first event occurred in the Upper Devonian, and the second
at the end of the Permian (250 million years ago), when only
two lines survived the P/Tr extinction event.
 The surviving species radiated and flourished throughout
the Triassic period.
 At the end of this period (206 million years ago) they faced
near extinction again, when only one genus survived.
 This event marked the end of the Triassic and the beginning of
the Jurassic, during which time the number of ammonite
species grew once more.
 The final catastrophe occurred at the end of
the Cretaceous period when all species were annihilated and
the ammonites became extinct.

11. Fossil fish

12.  The evolution of fish began about 530 million years ago
during the Cambrian explosion.
 It was during this time that the early chordates developed
the skull and the vertebral column, leading to the
first craniates and vertebrates.
 The first fish lineages belong to the Agnatha, or jawless
fish. Early examples include Haikouichthys.
 During the late Cambrian, eel-like jawless fish called
the conodonts, and small mostly armoured fish known
as ostracoderms, first appeared.
 Most jawless fish are now extinct; but the
extant lampreys may approximate ancient pre-jawed fish.

13.  The earliest jawed vertebrates probably developed during
the late Ordovician period.
 During the Devonian period a great increase in fish variety
occurred, especially among the ostracoderms and
placoderms, and also among the lobe-finned fish and early
sharks. This has led to the Devonian being known as
the age of fishes.

14. Pysa princepii

15.  Physa is a genus of small, left-handed or sinistral, air-
breathing freshwater
snails, aquatic pulmonate gastropod mollusks in the
family Physidae.
 hese small snails, like all the species in the family
Physidae, have shells that are sinistral, which means that
when the shell is held with the spire pointing up and the
aperture facing the viewer, then the aperture is on the left-
hand side.
 The shells of Physa species have a long and
large aperture, a pointed spire, and no operculum. The
shells are thin and corneous, and rather transparent.

16. Ostrea sculpturata

17.  This genus is very ancient. It is known in the fossil
records from the Permian to the Quaternary (age
range: from 259 to 0.0 million years ago).
 Fossil shells of these molluscs can be found all over
the world. Genus Ostrea includes about 150 extinct
species.
 Shell subovate, plicated, folds very irregular, superior
valve flat; disks with short irregular impressed lines;
cardinal area large; cartilage groove oblique, not
deeply impressed; muscular impression very long and
obliquely sublunate.