Plate 46CENOZOICMAMMALS
Plate 46CENOZOICMAMMALS
Another interesting representative of this order was the glyptodont. These peculiar mammals, which were ancestral to the present-day armadillos, developed at about the same time as the ground sloths.Glyptodon(Pl. 46), a typical glyptodont that has been reported from thePleistoceneof Texas, is quite characteristic of this group. This armadillo-like beast had a solid turtle-like shell that in some forms was as much as 4 feet high. From the front of the bone capped head to the tip of its tail, a large individual might be as much as 15 feet long. The thick heavy tail was protected by aseriesof bony rings, and in somespeciesthe end of the tail was developed into a bony heavily spiked club. Thecarapace(hard outer shell) of a large glyptodont is mounted at the Texas Memorial Museum.
Animals belonging to this order are called carnivores and are characterized by clawed feet and by teeth which are adapted for tearing and cutting flesh. The carnivores, or meat-eaters, were first represented by an ancient group of animals calledcreodonts, and this short-lived group first appeared in thePaleoceneand were extinct by the end of theEocene. They ranged from the size of a weazel to that of a large bear, and their claws were sharp and well developed. Their teeth, however, were not as specialized as those of modern carnivores, and the creodont brain was relatively small. It is assumed that these animals had a very low order of intelligence when compared to the more advanced carnivores of today.
These early meat-eaters were followed by more specialized carnivores which developed throughoutCenozoictime. Some examples of these are the saber-tooth catDinobastis(Pl. 47) and the dire wolfCanis diris(Pl. 47), both of which have been reported from the TexasPleistocene. Some remains of these unusual forms, representing the cat and dog families, are on display at the Texas Memorial Museum.
Pantodonts, known also asamblypods, were primitive, hoofed, herbivorous animals. They were distinguished by a heavy skeleton, short stout limbs, and blunt spreading feet. The pantodonts appeared first duringPaleocenetime and had become extinct by the end of theOligocene.
The members of this order are an extinct group of gigantic mammals commonly calleduintatheres.Uintatherium(Pl. 48), which is typical of the group, had three pairs of blunt horns, and the males had dagger-like upper tusks. Some of the uintatheres were as large as a small elephant and stood as much as 7 feet tall at the shoulders. The size of the brain in relation to the size of the body suggests that these animals were not as intelligent as most mammals. Uintatheres are known from rocks ranging fromPaleocenetoEocenein age. Uintathere remains have been reported from Big Bend National Park in Trans-Pecos Texas.
The earliest proboscideans, the elephants and their relatives, first appeared in the lateEoceneof Africa and were about the size of a small modern elephant but had larger heads and shorter trunks. Proboscidean development is marked by an increase in size, change in skull and tooth structure, and elongation of the trunk. Two well-knownfossilproboscideans are themammothand themastodon, both of which inhabited Texas duringPleistocenetime. The mastodons resembled the elephants, but the structure of their teeth was quite different (fig. 25). Moreover, the mastodon skull was lower than that of the elephant and the tusks were exceptionally large—some reaching a length of 9 feet.
Plate 47CENOZOICMAMMALS
Plate 47CENOZOICMAMMALS
There were several types of mammoths, and thewoolly mammothis probably the best known. This animal lived until the end of thePleistoceneand, like the woolly rhinoceros discussedbelow, is known from ancient cave paintings and frozen remains. Information gathered from these sources indicates that this great beast had a long coat of black hair with a woolly undercoat (Pl. 49).
Fig. 25.Sketches ofPleistocene(a) mastodon tooth (×⅙) and (b) mammoth tooth (×⅙).
Fig. 25.Sketches ofPleistocene(a) mastodon tooth (×⅙) and (b) mammoth tooth (×⅙).
During thePleistocene, mammoths were widespread over the United States, and their remains are abundant in many stream deposits of this age. Proboscidean bones have been reported from Pleistocene rocks in many parts of Texas, where they are commonly found in sand and gravel pits.
The perissodactyls, or odd-toed animals, are mammals in which the central toe on each limb is greatly enlarged. Modern representatives include the horses, rhinoceroses, and tapirs. Extinct members of the Perissodactyla include thetitanotheres,chalicotheres, andbaluchitheres, all of which grew to tremendous size and took on many unusual body forms.
One of the first perissodactyls wasHyracotherium(also calledEohippus), which is the earliest known horse (Pl. 47). This small animal, whose remains have been found in Big Bend National Park, was about 1 foot high and his teeth indicate a diet of soft food. Following the first horse, there is a longseriesoffossilhorses which provide much valuable information on the history of this important group of animals.
The record of the development of the horse is well represented in Texas, and the bones and teeth offossilhorses are common in certain parts of the State. Fossils of this type have been reported from theTertiaryof the Trans-Pecos, Gulf Coastal Plain, and High Plains regions of Texas, and the teeth ofPleistocenehorses have been found in sand and gravel pits in many parts of the State. Horse teeth (fig. 26) are particularly useful fossils as they may be accurately identified and used to determine the age of the rocks in which they are found.
Fig. 26.TypicalPliocenehorse tooth. Top view (a) andlateralview (b) of molar tooth (×½).
Fig. 26.TypicalPliocenehorse tooth. Top view (a) andlateralview (b) of molar tooth (×½).
This group of odd-toed mammals appeared first in theEocene, at which time they were about the size of a sheep. By MiddleOligocenetime they had increased to gigantic proportions but still had a small and primitive brain.Brontotherium(Pl. 48) was slightly rhinoceros-like in appearance and is believed to be the largest land animal that ever inhabited the North American continent. This animal was about 8 feet tall at the shoulders; a large bony growth protruded from the skull and this was extended into a flattened horn, which was divided at the top.
Plate 48TERTIARYMAMMALS
Plate 48TERTIARYMAMMALS
Although the titanotheres underwent rapid development during the earlyTertiary, these huge beasts became extinct during the middle of theOligoceneepoch. Titanothere remains have been reported from the Trans-Pecos region of Texas.
The chalicotheres were in some ways like the titanotheres, but they also exhibited many peculiarities of their own. The head and neck ofMoropus, a typical chalicothere, were much like that of a horse, but the front legs were longer than the hind legs, and the feet resembled those of a rhinoceros except that they bore long claws instead of hoofs. The chalicotheres lived in North America fromMioceneuntilPleistocenetime but were probably never very numerous, and their remains have not yet been discovered in Texas.
The rhinoceroses are also odd-toed animals, and there are many interesting and well-known fossils in this group. Thewoolly rhinoceros(Pl. 49) was aPleistocenetwo-horned form that ranged from southern France to northeastern Siberia. The woolly rhinoceros is well known from complete carcasses recovered from the frozen tundra of Siberia and from remains that were found preserved in an oil seep in Poland. These unusual specimens plus cave paintings made by early man have given a complete and accurate record of this creature. Although the woolly rhinoceros has not been reported from Texas, otherfossilrhinoceroses have been found in the High Plains and Gulf Coastal Plain of Texas. These fossils have been found in rocks ranging from MiddleOligoceneto latePliocenein age.
Baluchitherium, the largest land mammal known to science, was a hornless rhinoceros that lived in lateOligoceneand earlyMiocenetime. This immense creature measured approximately 25 feet from head to tail, stood almost 18 feet high at the shoulder, and must have weighed many tons. Remains of these creatures have not been discovered in North America, and they appear to have been restricted to Central Asia.
The artiodactyls are the even-toed hoofed mammals and include such familiar forms as pigs, camels, deer, goats, sheep, and hippopotamuses. This is a large and varied group of animals, but the basic anatomical structure of the limbs and teeth show well the relationship between the different forms. Artiodactyls are abundant fossils in rocks ranging fromEocenetoPleistocenein age and are common in rocks of this age in Texas.
These giant pig-like artiodactyls lived duringOligoceneand earlyMiocenetime and were distinguished by a long heavy skull that held a relatively small brain. The face was marked by large knobs which were located beneath the eyes and on the underside of the lower jaw, and although these knob-like structures were blunt they had the appearance of short horns. Certain of these giant swine attained a height of 6 feet at the shoulders and had skulls that measured 3 feet in length (Pl. 46). Entelodont remains have been found in the Miocene of the Texas Coastal Plain.
The first known camels have been reported from rocks of upperEoceneage, and these small forms underwent considerable specialization of teeth and limbs as they developed in size. Many of the camels that lived during the middleCenozoichad long legs which were well adapted to running and long necks which would have allowed the animals to browse on the leaves of tall trees.
The earliest known Texas camels were found in rocks ofOligoceneage, and camels, like horses, must have been abundant in Texas during thePleistocenefor their fossilized remains are common in many parts of the State.
Plate 49CENOZOICMAMMALS
Plate 49CENOZOICMAMMALS
The following books are recommended for the reader who wants to know more about fossils andfossilcollecting. The publications listed below cover various phases of historical geology and paleontology and range from children’s books to the more technical publications of the professional paleontologist. This list, however, is by no means all-inclusive and many other interesting and useful publications are available.
Dunbar, C. O.(1959) Historical geology, John Wiley and Sons, New York.
College-level text, well written and well illustrated.
Moore, R. C.(1958) Introduction to historical geology, McGraw-Hill Book Co., New York.
College-level presentation of earth history. Many illustrations of fossils.
Moore, Ruth(1953) Man, time, and fossils, Alfred Knopf, New York.
A readable account of fossils and their development throughout geologic time.
Panghorn, M. W., Jr.(1957) Earth for the layman, American Geological Institute, Washington, D. C.
Contains many valuable references.
Raymond, P. E.(1950) Prehistoric life, Harvard University Press, Cambridge, Mass.
College-level text.
Richards, H. G.(1953) Record of the rocks, Ronald Press, New York.
College-level earth history text.
Simpson, G. G.(1953) Life of the past, Yale University Press, New Haven, Conn.
Thorough, yet readable, introduction to paleontology.
Stirton, R. A.(1959) Time, life, and man: thefossilrecord, John Wiley and Sons, New York.
An introductory college text, most of which is of interest to adult level general readers.
Note:See alsosections on Paleontology and FossilsinEncyclopedia Americana, Encyclopaedia Britannica, and others.
Andrews, R. C.(1953) All about dinosaurs, Random House, New York.
Interesting and readable dinosaur book for junior high and high-school age.
Andrews, R. C. (1956) All about strange beasts of the past, Random House, New York.
Interesting and easy to read, this book deals largely with extinct and unusual mammals (junior high and high school).
Colbert, E. H.(1945) The dinosaur book, American Museum of Natural History, New York.
A classic among “popular” dinosaur books. For all age levels.
Colbert, E. H.(1957) Dinosaurs, American Museum of Natural History, New York.
This little booklet provides a well-illustrated introduction to the dinosaurs. For high school and adult-level readers.
Dickinson, Alice(1954) First book of prehistoric animals, Franklin Watts, Inc., New York.
Easy to read, well-illustrated book for grade-school age.
Dunkle, D. H.(1957) The world of the dinosaurs, Smithsonian Institution, Washington, D. C.
An easy to understand, amply illustrated introduction to the dinosaurs (high school-adult level).
Fenton, C. L.(1937) Life long ago, The John Day Co., New York.
Very good for advanced grade and high-school age.
Heal, Edith(1930) How the world began, Thomas S. Rockwell Co., Chicago.
An account of the beginnings of life. For upper grade through high-school age.
Markman, H. C.(1954) Fossils, Denver Museum of Natural History, Denver, Colo.
A well-illustrated general survey of fossils. For adult-level readers.
Matthews III, W. H.(1962) Fossils: An introduction to prehistoric life, Barnes and Noble, Inc., New York, [“In preparation” at time of first printing of Guidebook No. 2.]
This publication contains many collecting aids and much background material for amateur collectors. Contains also a brief review of earth history.
Matthews III, W. H.(1963) Wonders of the dinosaur world, Dodd, Mead & Co., New York.
Well illustrated, non-technical presentation of dinosaurs. For junior-high and high-school teachers.
Parker, B. M.(1942) Stories read from the rocks, Basic Science EducationSeries, Row, Peterson and Co., Evanston, Ill.
Well written and colorfully illustrated. For advanced grades and junior high.
Parker, B. M.(1948) Animals of yesterday, Basic Science EducationSeries, Row, Peterson, and Co., Evanston, Ill.
Well written and colorfully illustrated. For advanced grades and junior high.
Shaver, R. H.(1959) Adventures with fossils, Geological Survey, Indiana Department of Conservation, Bloomington, Ind.
Collection hints and general information on fossils. Particularly for the lower grades.
Shuttlesworth, D. E.(1957) Real book of prehistoric life, Garden City Books, Garden City, N. Y.
Survey of prehistoric life. For grade and junior-high levels.
Brown, Vinson(1954) How to make a home nature museum, Little, Brown and Co., Boston.
Contains suggestions for collecting, mounting, and displaying fossils and other objects of nature.
Camp, C. L., andHanna, G. D.(1937) Methods in paleontology, University of California Press, Berkeley.
Excellent discussion of collecting and preparation techniques.
Casanova, Richard(1957) An illustrated guide tofossilcollecting, Natureograph Co., San Martin, Calif.
Has collecting hints andfossillocalities for most of the States.
Collinson, C. C.(1959) Guide for beginningfossilhunters, EducationalSeries4, Illinois State Geological Survey, Urbana.
Clearly written, well illustrated, particularly for the lower grades.
Goldring, Winifred(1950) Handbook of paleontology for beginners and amateurs, New York State Museum, Albany, N. Y.
A complete summary of paleontology. For the advanced collector.
La Rocque, A., andMarple, M. F.(1955) Ohio fossils, Ohio Division of Geological Survey, Bulletin 54, Columbus, Ohio.
Rather comprehensive treatment of the invertebrates with several useful keys forfossilidentification.
Livingston, V. E., Jr.(1959) Fossils in Washington, Division of Mines and Geology, Department of Conservation, Olympia, Wash.
An introduction to the geology and fossils of Washington. Contains guide to collecting localities.
Simpson, B. W.(1958) Gem trails of Texas, Bessie W. Simpson, Granbury, Texas.
Field guide to Texas mineral,rock, andfossillocations. Contains numerous maps and well-described collecting localities.
Unklesbay, A. G.(1955) Common fossils of Missouri, University of Missouri Bulletin, Handbook 4, Columbia, Mo.
Written for the amateur; contains much general information of interest to the beginning collector.
Arnold, C. A.(1947) An introduction to paleobotany, McGraw-Hill Book Co., New York.
College-level textbook.
Beerbower, J. R.(1960) Search for the past, Prentice-Hall, Inc., Englewood Cliffs, N. J.
Good background text. Well illustrated. Has section on vertebrates.
Colbert, E. H.(1955)Evolutionof the vertebrates, John Wiley and Sons, New York.
Comprehensive and technical treatment ofvertebratefossils.
Cushman, J. A.(1948) Foraminifera, their classification and economic use, Harvard University Press, Cambridge, Mass.
College-level text containing large numbers of descriptions and illustrations of foraminifera.
Easton, W. H.(1960) Invertebrate paleontology, Harper & Bros., Inc., New York.
College-level text. Good illustrations, useful for identification.
Fenton, C. L., andFenton, M. A.(1958) Thefossilbook, Doubleday and Co., New York.
Comprehensive, easy-to-read, beautifully illustrated treatment of all types of fossils.
Jones, D. J.(1956) Introduction to microfossils, Harper and Brothers, New York.
College-level textbook with considerable information on collection, preparation, and the types of microfossils.
Moore, R. C., et al. (1953-1959) Treatise on invertebrate paleontology, Geological Society of America and University of Kansas, Lawrence, Kansas.
A technical reference for the more advanced collector. It is issued in several parts and contains latest classification.
Moore, R. C.,Lalicker, C. G., andFisher, A. G.(1953) Invertebrate fossils, McGraw-Hill Book Co., New York.
College-level reference with fine illustrations. Of value for purposes of identification.
Romer, A. S.(1945)Vertebratepaleontology, University of Chicago Press, Chicago.
A college-level textbook with numerous illustrations.
Shimer, H. W.(1933) Introduction to the study of fossils, The Macmillan Company, New York.
A relatively simple college-level presentation of plant and animal fossils.
Shimer, H. W., andShrock, R. R.(1944) Index fossils of North America, John Wiley and Sons, New York.
Comprehensive survey of the more common fossils of North America. Useful to the advanced collector and a most useful aid forfossilidentification.
Shrock, R. R., andTwenhofel, W. H.(1953) Principles of invertebrate paleontology, McGraw-Hill Book Co., New York.
Useful college-level reference for advanced collectors.
*Adkins, W. S.(1920) The Weno and Pawpaw formations of the Texas Comanchean: Univ. Texas Bull. 1856.
Descriptions and illustrations of many commonCretaceousfossils.
*Adkins, W. S.(1928) Handbook of TexasCretaceousfossils: Univ. Texas Bull. 2838.
Lists all fossils described from the TexasCretaceousprior to 1928, with many useful illustrations.
*Adkins, W. S., andWinton, W. M.(1919) Paleontologicalcorrelationof the Fredericksburg and Washita formations of north-central Texas: Univ. Texas Bull. 1945.
Contains descriptions and illustrations of many common LowerCretaceousfossils of north-central Texas.
Clarke, W. B., andTwitchell, M. W.(1915) TheMesozoicandCenozoicEchinodermata of the United States: U. S. Geological Survey Monograph 54, Washington, D. C.
A valuable guide to theMesozoicandCenozoicechinoderms of Texas.
*Frizzell, D. L.(1954) Handbook ofCretaceousForaminifera of Texas: Univ. Texas, Bureau Econ. Geol. Rept. Inves. No. 22.
A technical, but invaluable aid in the study of TexasCretaceousmicrofossils.
*Girard, R. M.(1959) Bibliography and index of Texas geology, 1933-1950: Univ. Texas Pub. 5910.
This valuable reference guide contains many references to Texas fossils. Note especially entries under Paleontology in the index.
Heuer, Edward(1958) Comments on the nomenclature revision of the Strawn and Canyon megafossil plates,inA guide to the Strawn and CanyonSeriesof thePennsylvanianSystemin Palo Pinto County, Texas, An Occasional Publication of the North Texas Geological Society, Wichita Falls, Texas.
Contains illustrations and latest name changes of many of the more commonPennsylvanianfossils of north Texas.
*King, R. E.(1930) Geology of the Glass Mountains, Part II, Faunal summary andcorrelationof thePermianformations with description of Brachiopoda: Univ. Texas Bull. 3042.
Contains descriptions and illustrations of numerous brachiopods from the Glass Mountains of Trans-Pecos Texas.
*Lee, Wallace, et al. (1939) Stratigraphic and paleontologic studies of thePennsylvanianandPermianrocks of north-central Texas: Univ. Texas Pub. 3801.
Contains an extensive faunal list and important collecting localities forPennsylvanianinvertebrates.
*Moore, R. C., andJeffords, R. M.(1944) Description of lowerPennsylvaniancorals from Texas and adjacent states: Univ. Texas Pub. 4401, pp. 77-208.
Describes and illustrates many of the more commonPennsylvaniancorals.
*Plummer, F. B.(1943) The Carboniferous rocks of the Llano region of central Texas: Univ. Texas Pub. 4329.
Containsgeologic map, locality data, and illustrations of many Carboniferous fossils.
*Plummer, F. B., andMoore, R. C.(1921) Stratigraphy of thePennsylvanianformations of north-central Texas: Univ. Texas Bull. 2132.
Describes and illustrates many of the more commonPennsylvanianfossils of north-central Texas.
*Plummer, F. B., andScott, Gayle(1937) UpperPaleozoicammonites in Texas: Univ. Texas Bull. 3701, pt. 1.
*Renick, B. C., andStenzel, H. B.(1931) The lower Claiborne of the Brazos River, Texas: Univ. Texas Bull. 3101, pp. 73-108.
Contains discussion and illustrations of many commonTertiaryfossils.
Sellards, E. H.(1955) Texas through 250 million years: Museum Notes No. 4, Texas Memorial Museum, Austin.
This little booklet provides a short geologic history of Texas along with a review of oil in Texas.
*Sellards, E. H.,Adkins, W. S., andPlummer, F. B.(1933) The geology of Texas, Vol. I, Stratigraphy: Univ. Texas Bull. 3232 (August 22, 1932).
This important publication will give the advanced collector much valuable information on the distribution of the rocks of Texas. Complete withgeologic map.
Stanton, T. W.(1947) Studies of some Comanche pelecypods and gastropods: U. S. Geological Survey Prof. Paper 211, Washington, D. C.
Describes and illustrates most of the more common LowerCretaceouspelecypods and gastropods of the State.
*Stenzel, H. B.,Krause, E. K., andTwining, J. T.(1957) Pelecypoda from the type locality of the Stone City beds (Eocene) of Texas: Univ. Texas Pub. 5704.
Descriptions and illustrations of many of the more commonTertiaryclams and oysters.
*Stephenson, L. W.(1941) The larger invertebrate fossils of the Navarro group of Texas: Univ. Texas Pub. 4101.
Contains descriptions of many common UpperCretaceousinvertebrates (exclusive of corals and crustaceans).
Stephenson, L. W.(1952) Larger invertebrate fossils of the Woodbineformation(Cenomanian) of Texas: U. S. Geological Survey Prof. Paper 242, Washington, D. C.
*Winton, W. M.(1925) The geology of Denton County: Univ. Texas Bull. 2544.
Illustrates and discusses the occurrence of manyCretaceousfossils.
*Winton, W. M., andAdkins, W. S.(1920) The geology of Tarrant County: Univ. Texas Bull. 1931.
Contains many illustrations of common north TexasCretaceousfossils.