Lecture 13 Flashcards
Compsognathidae
Compsognathids are a group
of very small to small theropods
from the Late J & Early K.
- Known from very few specimens.
- Their diet would have consisted
mainly of small lizards.
Nath= Jaw
Comps= elegant or dainty
Overall long digit
Compsognathus
Compsognathus lived during
the Late Jurassic (150 Ma) in
Europe.
- Known from two well-preserved
specimens: a holotype juvenile found
in Germany & and adult specimen
later found in France.
Compsognathus lived at the same time (Late Jurassic) and place
(southern Europe) as one of the oldest known birds – ___________
Archaeopteryx.
Archaeopteryx chasing a
juvenile Compsognathus.
§ Archaeopteryx is a
maniraptoran and thus has
many more evolutionary
novelties than Compsognathus.
Has clawed digits at the end of its wings and a bony tail
Solnhöfen Limestone
Compsognathus & Archaeopteryx
show exquisite preservation in Late
Jurassic strata called the
Solnhöfen Limestone.
-The lime mud was deposited as
tiny grains of calcium carbonate
(calcite) on the seafloor. The tiny
grains get in and around all the
nooks and crannies and thus leads
to excellent preservation,
much like mud and volcanic ash.
The Solnhöfen Limestone was deposited…
150 Ma when supercontinent
Pangea had rifted apart into its
northern and southern landmasses,
separated by the Tethys Ocean.
- Along the northern shores lay what is
now Europe, separated from the ocean
by a lagoon and an archipelago of small
islands.
The limestone is mostly devoid of fossils. Rare fossils include
both marine and terrestrial animals.
Yixian Formation
Next, we jump ahead in time to
the Early Cretaceous (~125 Ma)
Yixian Formation deposits
of Liaoning Province in
Northern China.
Like the Solnhofen Limestone
strata, the fossils here are
flattened thin and commonly
show exquisite preservation,
including integument.
Liaoning Province in northern China is
commonly referred to as
“Dinosaur
Pompeii” as many of the exquisite
fossils are preserved within volcanic
ash layers of the Yixian Formation.
The strata dates from 126 to 122 Ma.
Pyroclastic flows (hot ash and volcanic gases
Sinosauropteryx prima
Sinosauropteryx prima
(“Chinese lizard wing first”) was
discovered in 1996 and at that
time was the first non-avian
dinosaur discovered with
physical evidence of feathers!
Finally, there was clear evidence
for a dinosaur-bird connection.
64 caudal
vertebrae –
longest tail
per body
length of any
dinosaur
Had a curious
patchy
pattern
the first dinosaur
to have its colouration determined
based on physical evidence.
Sinosauropteryx (2010)
Through Melanosomes-
miniscule pigmentcontaining structures
within the keratin of
feathers
Size, shape and stacking likely represent different colours, as they do in modern birds.
Maniraptoriformes
Maniraptoriformes are coelurosaurs
with an additional evolutionary novelty:
pennaceous feathers!
-They also have an
increased number
of relatively
smaller teeth
(some toothless)
and include
diverse eating
strategies
Ornithomimosauria
Ornithomimosaurs (“bird-mimic lizards”) are
also referred to as the ‘ostrich dinosaurs’ as they
resemble today’s flightless birds with their long
necks & legs, and toothless beaks.
¡ Ornithomimosaur characteristics also include
long arms & long bony tails. They have 3
long fingers of approximately the same length
with gently curving claws.
Struthiomimus & Ornithomimus
Struthiomimus and Ornithomimus are common dinosaur fossils found
in Alberta, both in the Dinosaur Park Formation of Dinosaur
Provincial Park in southern Alberta (76.9-75.8 Ma), but also in the
Horseshoe Canyon Formation in the area around Drumheller (74-
67 Ma). They are also recovered from the Hell Creek Fm (68-66 Ma)
Gallimimus
Ornithomimosaurs are also
known from Asia. Mongolia
was home to Gallimimus 70 Ma.
Same time as the Tarbosaurus
