Lab/field assignment

1. Southern California
By: Lisa Ikada
LTCC

2. Introduction
In order to have a better understanding of the formation and
evolution of Earth, this presentation will examine: 3 different
types of rocks, the evolution of three different species (plant and
animal), and identify one of Steno’s Laws and Principles as well
as some unconformities. The research for this presentation was
collected in different areas of Southern California. Plants,
animals, and rocks were documented during nature hikes in Lytle
Creek, Ca and surrounding areas, with the exception of one tree,
which was found in my own backyard. After much research, this
is what I discovered.

3. Date Palm
(Ontario, Ca)
 Palm evolution began approximately 80 million years
ago during the late Cretaceous Period.
 The fossil record shows that the date palm has existed at least 50 million years.
 Though the exact date and origin are unknown, the date palm is believed to have
originated in what is now Iraq.
The date palm is a flowering species in the palm
family, Arecaceae. Native to hot and dry climates, the
date palm is one of the oldest fruit crops grown in
the arid regions of the Arabian Peninsula, North
Africa, and the Middle East.

4. Evolution of flowering plants (Angiosperm)
 During the early Cretaceous flowering plants began to appear, ending the
dominance of seedless plants and gymnosperms.
 They began to rapidly diversify during the middle of the Cretaceous.
 Angiosperms have adapted to nearly every terrestrial habitat (Monroe and
Wicander, 2015).
 Factors contributing to their success include: method of reproduction, flowers
(attracted pollinating animals), and enclosed seeds.

5. Blue Jay
The blue jay is a passerine bird, informally known as a songbird. The blue jay is
known for its “noisy calls” and is native to North America.
 Fossil record of passerines is limited and not well studied.
 The origin of passerines was dated at the Paleogene, much younger than usual
estimates (Selvatti, Gonzaga, and Russo, 2015).

6. Evolution of Birds
 Evidence indicates that birds evolved from a small groups of carnivorous dinosaurs
called theropods (The Origin of Evolution, 2003).
 Theropods were typically bipedal and ranged in size, from small and delicate, to
large.
 Archaeopteryx, 10 fossils of “feathered dinosaurs” were discovered in Germany in
1860.
 A fossil discovered in China more recently, Xiaotingia, is the earliest bird-like
creature known, dating back to the Late Jurassic.

7. Ground Squirrel
Ground squirrel are part of the family Sciuridae, consisting of small to medium-
size rodents. They are native to the Americans, Eurasia, and Africa.
 Fossils of tree squirrels date back to the Late Eocene Epoch.
 Very recently fossils were discovered in China of 3 “squirrel-like” species that lived
approximately 160 million years ago, dating back to the Triassic Period (Choi,
2014).

8. Evolution of Mammals
 The transition from cynodonts to true mammals took place during the Late
Jurassic.
 Indications that cynodonts were ancestors of mammals:
1. Cynodonts teeth were becoming double rooted, with somewhat differentiated
teeth used for specific functions.
2. Progressive change from reptile to mammal jaw are documented by fossil evidence
(Monroe and Wicader, 2015).
3. Middle-ear bones of mammals were originally jaw bones in early therapsids.

9. Mormon Rocks
(San Bernardino County, Ca)

10. Mormon Rocks continued
 The Mormon rocks are located along the San Andreas Fault in San Bernardino
County (off the 15 freeway).
 They are sedimentary rock.
 These rocks are sandstone conglomerate with walls up to 200 feet tall.
 They acquired their name from Mormon settlers crossing the Cajon Pass from Salt
Lake City, in 1851 (summitpost.org).
 They are nick-named Rock Candy Mountains.

11. Granite
(found in Lytle Creek, Ca)

12. Granite Continued
 Igneous rock
 Coarse-grained
 Consists mostly of feldspar and quartz
 Typically light colored
 Numerous other minerals can be present in granite.
 Mineral composition usually gives the granite a red, pink, gray, or white color with
dark mineral grains visible throughout the rock (King).

13. Diorite with xenoliths of darker rock
(found in Lytle Creek, Ca)
 Igneous rock
 Course-grained
 Nick-named the salt and pepper rock (color is typically speckled black and white)
 Composed of mostly sodium-rich plagioclase, hornblende, and biotite (King)
 Composition is intermediate
(compositionally equivalent fine- and
course-grained igneous rocks (Monroe and
Wicander, 2015).
 Forms from cooling magma

14. Mountains in Southern California
(off the 15 freeway)
 The principle of original horizontality tells us that sediments are essentially deposited in horizontal
layers due to gravity. We can see that these rock layers were deposited horizontally and tilted after
deposition. This tilt is an example of an angular unconformity.
 There are also
disconformities present,
as we can see areas of
erosion.

15. Mountains in Southern California
continued
• There is a tilt in the bottom-left layers of deposition (angular unconformity).
There is an erosional surface between these tilted rocks and the younger
rocks deposited above it.

16. References
 Choi, C. Q. (2014, September 10). Ancient Squirrel-Like Creatures Push Back
Mammal Evolution. Retrieved from https://www.livescience.com/47774-ancient-
squirrels-push-back-mammal-evolution.html
 King, H. M. (n.d.). Granite. Retrieved from https://geology.com/rocks/granite.shtml
 Monroe, J. S., & Wicander, R. (2015). The changing earth: Exploring geology and
evolution (7th ed.). Stamford, CT: Cengage Learning.
 Mormon Rocks. (n.d.). Retrieved June 03, 2018, from
https://www.summitpost.org/mormon-rocks/270028
 Selvatti, A. P., Gonzaga, L. P., & Russo, C. A. (2015). A Paleogene origin for crown
passerines and the diversification of the Oscines in the New World. Molecular
Phylogenetics and Evolution, 88, 1-15. doi:10.1016/j.ympev.2015.03.018
 The origin of birds. (n.d.). Retrieved June 09, 2018, from
https://evolution.berkeley.edu/evolibrary/article/evograms_06