AN ABSTRACT OF THE THESIS OF
Bonnie Carolyn Templeton for the Ph. D. in Botany (Name) (Degree) (Major)
Date thesis is presented
Title THE FRUITS AND SEEDS OF THE RANCHO LA BREA
PLEISTOCENE DEPOSITS
Abstract approved (Major professor)
More than 4,000 specimens of fruits and seeds were extracted from the matrix removed from inside the skulls of sabre-tooth cats
excavated from various pits in the Rancho La Brea deposits. Of this number, spproximately 1,445 specimens are involved in this study.
Many comparisons with modern fruits and seeds made it possible to
make identification of this material. There are 15 families com-
prising 20 genera and 30 species recorded in this report of the
Rancho La Brea Pleistocene flora. Of this number, four species
and four varieties are new to the Pleistocene floras. Eleven of the
30 species occur in the flora of the area today, eleven now occur in
areas so remote from the Rancho La Brea site that they could not
have been carried by flood waters into the areas of deposition, and
therefore, must have been living near to the asphalt beds in order
that entrapment could occur. Eight of the species are now extinct.
Based on the requirements of their modern counterparts, ecologically, many of the species live in riparian situations or more moist locations than prevail today in the area of deposition. The average rainfall for the range of a number of the modern representa- tives of the fossils was correlated. From these data it appears that the climate may have been cooler and more moist during the period of deposition, and the species occurring in southern California at that time would have required 2- to 25 inches for their continued ex- istence. It may be assumed that when this average dropped below
20 inches for long periods of time, the species either receded to areas with suitable rainfall or became extinct. THE FRUITS AND SEEDS OF THE RANCHO LA BREA PLEISTOCENE DEPOSITS
by
BONNIE CAROLYN TEMPLETON
A THESIS
submitted to
OREGON STATE UNIVERSITY
in partial fulfillment of the requirements for the degree of
DOCTOR OF PHILOSOPHY
June 1964 APPROVED:
Professor of Botany
In Charge of Major
( Head of Bo/any Depa tment
Dean of Graduate School
Date thesis is presented -;Cid_
Type d by Betty Hostetter and Muriel Davis PLEASE NOTE: Maps are not original copy. These pages tend to "curl". Filmed in the best possible way.
UNIVERSITY MICROFILMS, INC. ACKNOWLEDGMENTS
I wish to express my appreciation to the Los Angeles County
Museum for the use of the paleobotanical material from the Rancho
La Brea Pleistocene deposits, to its photographic department for the reproduction and use of early photographs of the area, and to Dr.
Herbert Friedmann, Director, for his encouragement in this re-
search.
I wish to thank my doctoral committee at Oregon State Univer-
sity, especially Dr. Henry P. Hansen, Dean, Dr. Roy Young, Head of the Botany Department, and Dr. Harry Phinney, Professor of
Botany, for their patience in what became a long and arduous task, their guidance, and encouragement.
I am particularly grateful to the herbaria of the University of
California at Berkeley, the University of California at Los Angeles,
Oregon State University, Rancho Santa Ana Botanic Garden, and the
Los Angeles County Museum for the privilege of using their collec- tions and acquiring samples of seeds and fruits for study.
I wish to express my very great appreciation to Mr. Hubert
McLain, Long Beach, California, for photographing many of the sub- jects in this thesis.
My appreciation also goes to the many people who provided seeds for my study, the librarians, and any others who in some way made this research possible. TABLE OF CONTENTS
Page
INTRODUCTION • • • 0 1
HISTORY OF DISCOVERY AND DEVELOPMENT • 3
PLANT-BEARING LOCALITIES .
MODE OF DEPOSITION AND AGE • • 42
MATERIALS AND METHODS 48
THE PROBLEM . ... •••0 •• • • 51
SYSTEMATIC DESCRIPTIONS . • •••••*. • ... 54
• PINACEAE Family — • • • 16 • 1, 11. • . 56
Pi nu s L ...... *a* . 56
Pinus muricata Don...... • • • • • 64 Pinus masoni var, breaensis n. var. . • • • • . 70
CUPRESSACEAE Family ...... 77
C upressus L. . . , ...... 77
Cupressus arizonica var. Hancockii n. var. . . 09 78
J uniperus L ...... • 85 Juniperus californica Carr.. . . • . • • • • 89
Juniperus Hanseni n. sp. . . . . • • V 0 93
IRIDACEAE Family , , . , . , . . . . a ...... 105
SisyrinchiumL L.. . . .— ...... • . .105 . 105 Sisyrinchium bellum Wats. . • . . .107 Quercus dumosa Nutt — . . . . . . .113 Quercus lobata Nee: . . . .118
POLYGONACEAE Family . • • 001 124
Rumex L. . • . . . —124 Rumex mexicanus Meism, . . . .125 Page
PORTULACACEAE Family 128
Calandrinia ciliata var. Menziesii (Hook.) Macbr. 129
Montia spathulata (Dough) Howell i . • • 133
ACERACEAE Family, 9 • • • 0 0 • • • • 0
136 A cer L. . • • • • •
Acer praecalifornicum n. sp._ 0 or • or • 137
Acer Negundo var. breaense n. var. • 141
CORNACEAE Family , • 0 • 145
Cornus L. . V • • • • 145
Cornus californica var. breaensea n. var. . • • 146 150 Cornus Stockii n. sp. • • 0 • •
153 ERICACEAE Family • • • • •
153 Arctostaphylo Adams, — • • . • Arctostaphylos insularis Greene . . . . . . . . 155 Arctostaphylos morroensis Wies. and Schreib. . . 155 Arctostaphylos pechoensis Dudl, ex Abrams . • • 161 Arctostaphylos tomentosa (Pursh) Lindl...... 164 Arctostaphylos viscida Parry. . . . • • • • • • 168
Xylococcus bicolor Nutt. . . . . • • 0 • I • • 172
SCROPHYLARIACEAE Family • . • • 177
Antirrhinum L, . . — • 177
Antirrhinum Nuttallianum Benth. • • • . • • • 0 177
Orthocarpus Nutt. _ . . • • • p • • 182
Orthocarpus purpurascens Benth. . • • • • 183
187 ROSACEAE Family • 0 .0 • • •
187 Rubus • • • • • • • • •
Rubus vitifolius Cham, and Schlecht. • • 187
ANACARDIACEAE Family, • . 189
Rhus diversiloba Torr and Garay , 191
Page
RUBIACEAE Family • OOOOO O OO • 195 • •
Galium L. • • • • ...... • 195 Galium trifidum Gray 197
CAPRIFOLIACEAE Family . • • . • . • . • . • • • 199
Sambucus L ...... • .. • • • • • • • 199
Sambucus mexicana Presl. ex DC. . • • • • • • 200
COMPOSITAE Family ..... • • • • • • • • • 203 Calycadenia tenella (Nutt ) 206 Hemizonia fasciculata (DC.) . . • . . • • • 206
DISCUSSION 0.40* ...... Q0.0.0 213
SUMMARY . ,04,••0049000 ...... • 216
BIBLIOGRAPHY . ...... . . • • • 217 LIST OF FIGURES
Figure Page
1 Rancho La Brea Pleistocene deposits looking west
from center of area, 1913 ...... • • 8
2 Small lake in southeast part of Rancho La Brea deposits,.1913 8
3 Cypress tree excavated from Pit 3 at 12 feet . • • • 17
4 Stump of another tree excavated from Pit 3 at depth of 18 feet 19
5 Pit 3 at depth of 27 feet; end of excavation 21
6 Mass of plant material with bones in Pit 4 at depth of 11 feet 24
7 Pit 4 at depth of 27 feet; end of excavation. • • • 24
8 Pit 9 at depth of 8 feet . • . • • ..... • • • . 26
9 Pit 9 at depth of 12 1 ft. showing socket of scapula where pine cone was found 28
10 Pit 9 at 18 foot depth showing huge asphalt wall with masses of wood and other plant material embedded in it 31
11 Pit 9, same as in Figure 10 but at about 24-foot depth, showing masses of wood below asphalt wall • 32
12 View of Pit 10, showing funnel-shape deposit . 36
13 View of roof of clay 8 feet below surface that covered the deposit in Pit 13 36
14 View of Pit 61 with Pit 67 in background 40
15 Two cones of Pinus muricata Don. (modern) 60
16 Cone of Pinus attenuata Lemmon (modern) 63
Figure Page
17 Fossil cone of Pinus muricata Don. and seeds. • 66
18 Close-up of two scales of fossil cone in Figure 17 . 68
19 Pinus muricata Don. (modern), typical form . 69
20 Pinus Masoni var. breaensis n. var.. . 72
21 View of smaller cone of same species . 74
22 Cupressus arizonica var. Hancockii n. var. 81
23 Cone assigned to new variety of Cupressus. . 84
24 Cone of modern Cupressus arizonica Greene . 84
25 Cone of Cupressus macrocarpa Hartw. . • • 84
26 Fossil Juniperus californica Carr. seeds from Pit 3 and Pit A . • • 91
27 Modern seeds of Juniperus californica Carr. . 92
28 Juniperus Hanseni n. sp.. . . . 97
29 Seeds and berries from Pit 67 and Pit 4 o
Juniperus Hanseni n. sp.. . 99
30 Several species of modern Juniperus used in comparison with the new fossil species . 101
31 Modern fruits and seeds of Juniperus mexicana . 104
32-33 Fossil and modern seeds of Sisyrinchium bellum Wats 109
34 Fossil acorn of Quercus agrifolia showing insect infestation 111
35 Fossil and modern young acorn and cups of Quercus dumosa Nutt.. • • • ▪ . 115
36 Fossil acorns ofQuercus dumosa Nutt. . • . 116 Figure Page
37 Modern acorns of Quercus dumosa Nutt. 117
38 Fossil acorns of Quercus lobata Nee 121
39 Modern acorn of Quercus lobata Nee' .. .. . 122
40 Fossil fruit of Rumex mexicanus Meism. 127
41 Modern fruits of Rumex mexicanus Meism. • • 127
42 Fossil seeds of Calandrinia ciliata var. Menziesii (Hook.) McBr. . .... . . . . 131
43 Modern seeds of Calandrinia ciliata var. Menziesii (Hook) McBr• . • • • • • . 131
44 Fossil seeds of Montia spathulata (Dougl.) 135 ..... • . • • • • • • • • •
45 Modern seeds of Montia spathulata (Dougl.) Howell.. • • • • . • • . ..... 135
46 Acer praecalifornicum n. sp. found in Pit 3 . . . . 140
47 Acer Negundo var breaensum n• var...... 142
48 Modern samara and seeds of Acer Negundo var. californicum Sarg. . . .... .. • • • • 144
49 Cornus californica var. breaensea n. var. . . . . 149
50 Modern seeds of Cornus californica C.A. Mey. . 149
51 Cornus Stockii n. sp. . • ...... • . . 152
52 Cornus stolonifera Michx• (Modern) 152
• • 158 53 Arctostaphylos insularis Greene (fossil) . •
54 Arctostaphylos insularis Greene (modern) • • • • 158
55 Fossil nutlets of Arctostaphylos morroensis Wies. and Schreib• • • • . • • • • • • • • • • • • 160 Figure Page 56 Modern nutlets of Arctostaphylos morroensis . . . . 160
57 Fossil nutlet of Arctostaphylos pechoensis Dudl. ex Abrams . . . • . . • 163
58 Modern nutlets of Arctostaphylos pechoensis Dudl. ex Abrams .. •. — . • • * . . . 163
59 Fossil stone of Arctostaphylos tomentosa (Pursh) Lindl 167
60 Modern stone of Arctostaphylos tomentosa Dudl. ex Abrams . . . • • • • • . 167
61 Fossil nutlet of Arctostaphylos viscida Parry . . . 171
62 Modern nutlets of Arctostaphylos viscida Dudl. ex Abrams • • • • . . 171
63 Fossil stone of Xylococcus bicolor Nutt.. . . . 175
64 Modern stone of Xylococcus bicolor Nutt. . . 175
65 Fossil seeds and capsule of Antirrhinum Nuttallianum Benth. . . • • . 179
66 Modern seeds and capsule of Antirrhinum Nuttallianum Benth. . . • • • 179
67 Fossil seed of Orthotarpus purpurascens Benth. . . 185
68 Modern seeds of prthoca-rpus purpurascens Benth. • . 185
69 Fossil seed of Rubus vitifolius Chain. and Schlecht . . 188
70 Modern seed of Rubus vitifolius Charm and Schlecht . 188
71 Fossil seed of Rhus diversiloba T. and G. . . . 193
72 Modern seeds of Rhus diversiloba T. and G. . . . , . 193
73 Modern fruits of Galium. Nuttallii Gray . . . . 196
74 Modern fruits of Galium trifidum L. 196
75 Fossil fruits of Galium trifidum L. . . . 198
Figure Page
76 Fossil seeds of Sambucus mexicana Presl.. . . 202
77 Modern seeds of Sambucus mexicana Presl. . 202
78 Modern seeds of Sambucus coerulea Raf. . . 204
79 Fossil achene of Calycadenia tenella (Nutt. ) T. and G. . • • 207
80 Modern achenes of Calycadenia tenella (Nutt. ) T. and G. . . .... . 207
81 Fossil achenes of Hermizonia fasciculata (DC. ) T. and G. 211
82 Modern achenes of Hemizonia fasciculata (DC.) T. and G. . 211
LIST OF CHARTS
Chart Page
I The area of Rancho La Brea deposits is shown and the approximate location of the various pits excavat- ed in it. ...... .. . . . 11
II A diagram showing the quadrat method used in ex- cavations of pits in the Rancho La Brea deposits. This enabled the excavators to cite locations of the specimens uncovered in each pit 13
III Paleontological evidence in various excavations of Rancho La Brea deposits. . . . . . 15
IV A diagram showing the excavations in Pit 3 20
V A diagram of the extent of the excavations in Pit 4 and showing the three separate channels in which fossils occurred.. . . , ...... . . . . 25
VI Shows diagram of excavation work in Pit 9. Dotted lines show outline of excavation work. continuous lines indicate limits of fossiliferous deposit 34
VII Shows extent of excavations in Pit 13 37 LIST OF MAPS (Showing distribution based on studies of field collections.) Map Page 1 Juniperus californica Carr 94
2 Sisyrinchium bellum Wats 106
3 Quercus agrifolia Nee 112
4 Quercus dumosa Nutt. 119
5 Quercus lobata Nee" 123
6 Calandrinia ciliata var. Menziesii (Hook.) McBr. . 132
7 Montia spathulata (Dougl. ) Howell . 135a
8 Acer Negundo var, californicum. . 138
9 Cornus californica C A Mey 147
10 Arctostaphylos insularis and A. morroensis Wies and Schreib 156
11 Arctostaphylos pechoensis Dudl. ex Abrams. 165
12 Arctostaphylos tomentosa (Pursh) Lindl. 169
13 Arctostaphylos viscida Parry 173
14 Xylococcus bicolor Nutt 176
15 Antirrhinum Nuttallianum Benth 181
16 Orthocarpus purpurascens Benth 186
17 Rubus vitifolius Cham. and Schlecht 190
18 Rhus diversiloba T, and G 194
19 Sambucus mexicana Presl. ex DC. 205
20 Calycadenia tenella (Nutt.) T. and G. . 208
21 Hemizonia fasciculata (DC,) T. and G. 212 THE FRUITS AND SEEDS OF THE RANCHO LA BREA PLEISTOCENE DEPOSITS
INTRODUCTION
The faunal aspects of the various pits in the Rancho La Brea deposits at Los Angeles, California, have been well described by a number of zoologists and paleontologists. The extent of botanical material in these Pleistocene beds has been referred to only briefly in paleontological papers and accounts of the fossil animals encounter- ed in excavations of these asphalt deposits. The brief references were based mainly on a single paper by Frederick H. Frost, "The
Pleistocene Flora of Rancho La Brea" (1927) in which he reports on six species of plants, and a paper by H. L. Mason on "Fossil Records of Some West American Conifers" (1927) which includes the pine cones found in these deposits.
Since the appearance of these two papers, no work has been done on the occurrence of plant material in a number of pits in these fossil beds. Because of this, and because much can be learned from the knowledge of the kinds of plants that grew in this area during the time the deposition of animals and plants was taking place, this study is undertaken.
With the delineation of the fruits and seeds that have been ex- tracted from matrices in these Pleistocene asphalt beds the plant life in the past can be more completely known. The geographical relationship of plants could then be correlated with other known
Pleistocene deposits and a phytogeography of the California coastal
region eventually interpreted. Also, because plants are as a rule
excellent indicators of life zones and reflect in their present distribu-
tion the climatic conditions over geographic regions, the known
species occurring in the Rancho La Brea deposits may be expected to yield interesting information regarding the climate during the peri-
od of their accumulation. 3
HISTORY OF DISCOVERY AND DEVELOPMENT
So far as is known, the first record of the tar seeps or "springs
of pitch" in the Los Angeles region was made by Gaspar de Portola
in his diary of the Portola California Expedition of 1769-1770 (70, p.
53). Long before this, however, the Indians of southern California knew of these tarry deposits. They traveled many miles to gather this material, which they called "brea", to use in the thatching of their houses, making baskets and arrow shafts and mending of pot- tery.
In 1884, a second report appeared on the occurrence of bitumi- nous springs near Los Angeles by the French explorer Duflot De
Mofras (22, p. 357). In the account of his exploration of the territo- ries of Oregon and California he describes the asphalt deposits, and on a map accompanying this report he indicates the source of the bitumen in the plains west of Los Angeles.
In 1849 the first cartographic record of the asphalt deposits, which may be identified with those of Rancho La Brea, was made by
E. 0. C. Ord (62, p. 127). Issued with Lieutenant Ord s report to
General Riley, on the geology and topography of California, is a topographical sketch map of the Los Angeles plains and vicinity. On this map, the location of pitch springs is shown at a point several miles west of Los Angeles and south of the gap, now known as 4
Cahuenga Pass, in the Santa Monica Mountains.
In 1853, William G. Blake (7, p. 76), geologist of explorations for a railroad route from the Mississippi Valley to the Pacific Coast,
examined the Los Angeles region as a part of the program. In his re-
port (1856) he describes the bituminous deposits, possibly those of
Rancho La Brea, near Los Angeles.
It was not until 1875, however, that the occurrence of skeletal remains of extinct animals in the asphalt deposits of Rancho La Brea was made known. In that year William Denton (19, p. 185) gave an account of his visit to the brea ranch of Major Henry Hancock, and
described the asphalt area which was then being excavated for their tar content. He tells of a large canine tooth, later determined to be that of a sabre-toothed cat, presented to him by Major Hancock, as well as other bones he acquired at the time.
Denton s account apparently went unnoticed by scientists for no interest in the occurrence of the fossils was manifested until 1905.
Late in that year W. W. Orcutt (61, p. 37) of Los Angeles recognized the importance of the fossils in these deposits when he, with Frank M.
Anderson, visited the Rancho La Brea area. A number of bones he collected on that visit was sent to Dr. John C. Merriam of the Uni- versity of California.
The significance of this discovery led Madam Hancock Ross to permit the University of California to excavate for fossils. Subsequently, explorations were carried on at intervals from 1906 to
1913. The Southern California Academy of Sciences, Occidental Col-
lege, and the Los Angeles High School also obtained collections during
that period.
In 1913, Mr. G. Allen Hancock granted Los Angeles County the
exclusive privilege to excavate at Rancho La Brea for two years.
During this period the excavations were conducted by the Los Angeles
County Museum. Then, in May 1915, Mr. Hancock generously gave the tract of land, approximately 23 acres, on which the famous fossil beds occur, to Los Angeles County with a request that the scientific features of the site be adequately exhibited and preserved.
An official deed, executed May 19, 1924, by G. Allen Hancock, granted to the County of Los Angeles the 23 acres of Rancho La Brea for the purpose of preserving this area and for Public Park purposes.
The name of "Rancho La Brea" had been changed at that time and is known as Hancock Park in honor of the donor. 6
PLANT-BEARING LOCALITIES
During the early years at Rancho La Brea, as far as is known,
there were no native trees or shrubs of any height in the area. There
were trees planted as windbreaks (Figure 1) somewhat distant from
the asphalt beds, and some Eucalyptus trees were planted about the
Hancock home, barn, shop, and other buildings, and beside the near-
by lake (Figure 2). Whether any native trees occurred in close prox-
imity and had been removed earlier to make room for oil derricks
and agricultural development has not been determined.
In Father Crespe s letters on "The Portola Expedition" (8, p.
149) he speaks of this area as being called the "Spring of the Alders".
A topographical map, made in 1893-1894, shows a number of springs
and marshes in the La Brea area, and several streams leading south- ward toward Ballona Creek. It is not certain whether the trees oc-
curring in the area of Rancho La Brea during the time the Portola
expedition passed through were alders or were sycamores and inter- preted as alders. Either one or both of these trees could have oc-
curred in this area during that time.
As will be shown from the following account of the botanical aspects of the various excavations of the Rancho La Brea deposits, there must have been many trees, shrubs, and plants growing nearby or in the foothills of the Santa Monica Mountains to the north of these deposits. 7 Figure
A general view of Rancho La Brea, looking northwest from near the center of the deposits. The Salt Lake Oil Field and Santa Monica Mountains are in the background.
(Los Angeles County Museum photograph, about 1913. )
Figure 2
A view of the lake in the southeast area of Rancho La Brea, looking northwest; Hancock residence in the background.
(Los Angeles County Museum photograph, about 1913. )
9
From July 8, 1913, to December 14, 1915, the Rancho La Brea deposits had been extensively excavated by the Los Angeles County
Museum. Approximately one hundred pits had been dug during this period (Chart I); many of them proved barren of any paleontological material. Later, from about 1929 and for a few years thereafter, several other pits--Pit 101, Pit A, Pit B, Pit C, and Pit D--were excavated.
To facilitate the keeping of records on the excavations a quadrat system was used. This consisted of crisscrossed lines stretched across the pits from permanent stakes at intervals of three feet.
This laid out the pit area into 3-foot squares. Each square was indi- cated by a letter and number (Chart II) so that a specimen excavated in any one of, the squares, say C-6, would bear on its label the letter and figure of the square in which it occurred, the depth at which it was found, and the pit number. Thus, 3: C-6, 101 ft. on the speci- men indicated that the specimen occurred in Pit 3, Sect. C-6, at
101 ft. depth.
This quadrat method was used almost entirely throughout all the earlier excavations, but so far as can be determined was not fol- lowed in the excavations of Pit 101, and Pits "A", "B", "C", and
Since the extent and occurrence of botanical material in the numerous deposits at Rancho La Brea has not been reported it is of 10 Chart I
The area of Rancho La Brea deposits is shown and the approximate location of the various pits excavated in it.
11
SIXTH STREET •51
26 • , • 8 '42 28 • 7
U. OF CALIF. • 35 PITS _Ali:. cot
...... „....24—• ,60 —...... ---- , •38 44 80 --• V89 77 ,' \ PI T. A .41 79 ---• ..../ 78 •39 90 85 6 •----f--29 10 75 34 0 71 56 4 • 20 • 18 0 •21 ._ • 300 SHACK ').3_ 31k • 25 -., • 84• 83 016 Cil • 52 •32 • 94 •95 OCCIDENTAL 19 • • 64 COLLEGE PIT ACADEMY OF 62 SCIENCE PIT r 17 /v6643
\63. 57 65 ..„.•••• 72\ 49 58 '59 WILSHIRE BLVD.
1400 FEET RANCHO LA BREA-FOSSIL BEDS 12 Chart II
A diagram showing the quadrat method used in excavations of pits in the Rancho La Brea deposits. This enabled the excavators to cite locations of the specimens uncovered in each pit. 1 3
' N VI It VI `0
a ..., •■• \
‘ _ .■, \ /
■ x (------I N
‘ (3 0 \
\ ii. ir.
■ Ia.' i N ‘ 0 7/1.1 0 8\ N eI I 1 t-V 0 U t. t j o 4\ ce) . .6 ■ mg ea \ cl 4 <4\
..— c4 Co) V Ii) 4) ■∎
4tk• . 4) \ NN \ 14 important interest to present here the abundance of paleobotanical material occurring in a number of deposits, The information for the occurrences of plant materialwas gleaned from field notes made by the excavators during 1913 to 1915„ From Chart III it will be noted that no paleontological material, zoological or botanical, was found in some of the pits. These may be considered as exploratory in nature. In some of the pits only faunal material was found, in some both faunal and floral specimens were found, while in a few only botanical specimens had been reporter. Only .the pit s containing botanical material will be discussed here.
Botanical aspects of Pit 3: This pit is remarkable paleontologi- cally because of the great proportion of the sabre-toothed cat among ani- mals, the tree among plants, and the fine preservation of all materi- al found in the excavation.
What appeared to be the stump of a tree (Figure 3) was exposed in D-2 at 41 feet below the surface. Subsequent excavation uncovered and exposed the tree to its base, 12 feet below the surface. It was found rooted in a sloping bank of what was once a gully. Many roots, including some of the large ones (see p. 79 ), penetrated the adjacent wall of the pit almost horizontally; others projected downward into a mass of pure clay beyond which no asphaltum appeared.
The apex of the tree appeared to have been either burned or rotted off. At approximately 34 feet below the apex a heavy branch,
15 CHART III Paleontological Evidence in Various Excavations of Rancho La Brea Deposits.
Plant Animal Plant Animal Pit No. remains remains Negative Pit No, remains remains Negative
Ito 2 X 57 X
3 to 4 X X 58 to 59 X
5 to 8 X 60 to 61 X
9 to 11 X X 62 to 64 X
12 X 65 to 66 X
13 X X 67 X X
14 to 15 X 68 to 71 X
16 X X 72 X
17 X 73 X
18 to 24 X 74 to 76 X
25 X 77 X
26 to 34 X 78 to 79 X
35 to 37 X 80 to 83
38 to 42 X 84 to 89 X
43 to 44 X 90 X
45 to 48 X 91 X X
49 to 51 X 92 to 100 X
52 to 56 X 16 Figure 3
Tree trunk removed from Pit 3, which was found rooted in a clay bank, beneath the asphaltum, 12 feet below the present surface of the ground.
(Los Angeles County Museum photograph. ) 17 18 ten inches in diameter, appeared at right angles to the trunk. All about this branch and about the trunk quantities of brush, twigs, wood, leaves and bones of all sorts were packed solidly in the tarry matrix.
Directly beneath the tree the earth was loose and bones totally lacking.
In removing the tree from the pit, numerous roots and drooping branches were cut off because these were so entangled with the bones that the excavators felt the removal of either the tree or the bones would have otherwise been impractical.
Abundant wood was encountered over nearly the whole pit at a depth of 12 feet, in places "seriously interfering with digging".
At 151 feet in F-3, another stump of tree was exposed during
excavation. This extended down to 18 feet. Further excavation found it to be an inverted crotched section of a tree, the arms of the
crotch projecting downward, giving the whole an appearance of an upright stump (Figure 4). In this crotch was found an upright sec- tion of a log four feet long, which was believed to have been from the same tree.
The final excavation of Pit 3 extended it in size to approximate-
ly 35 feet in diameter and a depth of 27 feet. Chart IV shows the
area covered in the excavation, and Figure 5 shows the final depth
at which excavations were terminated in this pit.
Botanical aspects of Pit 4: This pit was considered remark- able for the richness of its contents and their very goodpreservation. 19
Figure 4
Another stump of a tree, shown as it was uncovered in the matrix of Pit 3, Section F-3, at the 18-foot depth, its position inverted. A section of log is seen resting in the crotch of two branches. (Los Angeles County Museum photograph).
20
2,
S....flews. ts,nro. Gu ib hr;41 rl.• t iq tate.. fl it gr .147..0., Ni?e. • y/
- Ci,a31/ of Bo,a D•1..sit 4 Pit "
Chart IV
A diagram showing the excavations in Pit 3. (Los Angeles County Museum Photograph) 21
Figure 5.
Pit 3 - excavated to the depth of 27 feet. (Los Angeles County Museum Photograph) 22
At seven feet below the surface, the matrix here was of the very best, both for its preservative quality and the ease with which it was worked. Down to this point no discoveries of animal were men- tioned but small brush and roots in the adjacent walls and occasionally across the pit at this level was noted.
At 121 feet in C-2, considerable brush with an occasionalblock or chunk of wood was encountered.
Numerous seeds "resembling those of apple" were found in
C-5 at four feet, and quantities of leaves in D- and E-7 were en- countered at five feet.
Section C had been worked down to 15 feet clear across to the wall, and as Section B was approached in this excavation great
quantities of brush were encountered and found to replace bones at
this level. It was especially noted that in Sections B-4 to C-5 at
from 13 to 16 feet,great quantities of brush were encountered in
this excavation (Figure 6).
Pit 4 was slightly smaller in diameter than Pit 3. Chart V
shows the extent of excavations. The main fossiliferous mass ex-
tended to a depth of 16 feet, then continued downward in three sep-
arate, smaller channels to depths of 19, 24, and 25 feet. Figure 7
shows this pit at the 25-foot depth.
Botanical aspects of Pit 9: The excavation of this pit showed
it to be a huge fissure (Figure 8) that had filled with tar and sand 23 Figure 6
A mass of plant material with bones in Pit 4, Sect. A-5 to B-6, at depth of 11 feet. Mass of plant material may also be seen in area above the bones. (Los Angeles County Museum photograph)
Figure 7
Pit 4, shown at the depth of 27 feet, and the end of the excavations.
(Los Angeles County Museum photograph) 24 25
Chart V
A diagram of the extent of the excavations in Pit 4 and showing the three separate channels in which fossils occurred.
(Los Angeles County Museum Photograph) 26
Figure 8
Pit 9 at the 8-foot depth of its excavation, looking south- east. Further excavations had shown it to be a huge fis- sure filled with tar and sand where animal and plant materials were trapped. (Los Angeles County Museum Photograph) 28
Figure 9
Pit 9 at 121-foot depth, where a pine cone was found embedded in the socket of the scapula of an elephant in Sect. J-14. (Los Angeles County Museum Photograph) 29
in Sections I- and J-15. At 16 feet and below, wood was found extend-
ing clear across bottom to east wall in Sections G and H in as great
quantity as at any time in any part of this pit.
Wood became scarce along southern end of the pit; absent in
Section J below 14 feet, and in Section I below 16 feet. It was "still
troublesome" in Section G- and H-1-3, -14 and -15, while a consider-
able quantity appeared below 15 feet near wall in Section F.
A piece of wood, nearly eight inches in diameter, was en-
countered close to and parallel with an ulna of an elephant in Sections
G-12 and -13 at depth of 18+ feet.
Wood was encountered in Section M-14 at depth of 11 feet, and
was found to be very troublesome at 20 feet in F-11.
Considerable mass of twigs and small branches, lying mostly
horizontally, occurred in J-15 at depth of 17 feet, This mass was
lying against a hanging wall of asphaltum which, just below this point,
apparently became nearly vertical.
Masses of wood were still being found at a depth of 22? feet in
G-12 and -13 in which were embedded bones and bear teeth. The bones were considered worthless and the wood was not much better preserved than the bones. The matrix in this area was the most tar- ry of any portion of the pit and should have rendered the paleontologi- cal material well preserved. The fact that the material was not well preserved, it was believed, may suggest that this material may 30 have been decayed before being covered with asphaltum and becoming embedded.
The matrix in I- and J-13 to -14, which was composed almost entirely of tarry sand, contained little wood, while in Sections G and
H adjoining it the area was choked with wood.
Great quantities of wood were encountered in Section F-11 at
22-foot depth, and in Sections K- and L-15 a mass of wood was ex- cavated at a depth of 15 feet.
As the excavators worked down to 161 feet they encountered what appeared to be a tree in Section K-15. Upon further excava- tion, the tree trunk was found to extend from Section K-13 at 17 feet down to 19 feet in Section J-16. It measured 12 inches in diameter and seven feet long and was the second largest tree trunk removed
from any pit. Kagen (one of the excavators) reports, "working into wall in Section K-15 at 18-20 feet, where wood has been so trouble-
some. Nothing of value in sight."
A big mass of wood was encountered below the asphalt wall in
Sections K- and L-15 at a depth of 18 feet. This wood was well pre-
served. Figure 10 shows this material along with bones projecting through it. This mass of wood extended well under the asphalt wall, but contained, so far as could be seen, only an occasional bone (Fig- ure 11).
Excavations in Sections F and G-10 and -11 produced abundant 31
Figure 10
Pit 9 in Sect. L-15, at 18-foot depth, showing huge asphalt wall with masses of wood and other plant material embedded in it. (Los Angeles County Museum Photograph) 32
Figure 11
Pit 9 in Sect. L-15 (same area as Figure 10, but a lower depth) showing masses of wood occurring further down below elephant femur and humerus. (Los Angeles County Museum Photograph) 33 wood at and below 12 feet but almost no bones above 14 feet. Great quantities of wood continued over into Section M-16 from below 13 feet down to 171 feet.
A tree trunk, with a diameter of 15 inches, standing on end, was first encountered in Section E-11 at 11-foot depth. Further ex- cavations found it to extend down across J- and K-15 to the 19-foot depth. It was cut into portions and taken out in the course of the excavation. In these sections the "large pieces of tree trunk looked more valuable than the few bones being secured. "
An interesting feature of the pit was the great mass of hard, yet plastic, asphaltum, that covered with an impervious roof the ex- treme south end of the deposit, and was extended on one side into the earth to a distance of seven feet or more. Chart VI shows the extent of the excavations in this pit.
Botanical aspects of Pit 10: This pit appeared to be funnel shaped and pinched in rapidly below four feet (Figure 12). As exca- vation progressed, masses of leaves and small twigs were encoun- tered in F-10 and northeast half of F-10 at 3+ feet. Again, at 5+ feet great quantities of leaves and twigs, particularly in northwest half of funnel, were encountered, while the opposite half consisted mostly of hardened, barren asphaltum. The pit was excavated to
15 feet but most of the fossiliferous material occurred above eight feet. 34
r
Chart VI
Shows diagram of excavation work in Pit 9. Dotted lines show outline of excavation work; continuous lines indicate limits of fossiliferous deposit. (Los Angeles County Museum Photograph) 35
Botanical aspects in Pit 11: In the excavation of this pit, some
small twigs and leaves were encountered above 5 feet. Because no
bones were found below three feet, the excavation of this pit was dis-
continued at 84 feet.
Botanical aspects in Pit 12: The results of the excavation of
this pit was about the same as that of Pit 11, with only a piece of wood
1/2 inch in diameter and five inches long encountered at a depth of
41 feet.
Botanical aspects of Pit 13: This is one of the important pits,
because of the high percentage oftGiant Sloth fossils it contained. No-
table feature of Pit 13 was the evidence that the bone deposit had been at
some time almost, if not entirely, covered by a domed roof of clay
(Figure 13). Although no mention of the occurrence of plant material
was made in the extensive notes on this pit, in view of later findings
of plant material in the matrix removed from skull cavities this pit
is included. Chart VII shows the extent of excavations of this pit.
Depth of excavation was 25 feet,
Botanical aspects of Pit 16: This pit was an almost circular
hole, with nearly vertical walls down to 20 feet. At 24-foot depth
the deposit contracted rapidly and pinched out to a mere crack at
27 feet. As in the case of Pit 13, the notes contained extensive
records of bones, but plants were mentioned only briefly. Much brush and roots were encountered at eight feet. At approximately 36
Figure 12 Shows Pit 10 to be a funnel-shaped deposit. Masses of leaves and twigs were found at about 3 to 54 feet. Datum established for Pit 10 is 164. 7 feet above sea level.
(Los Angeles County Museum Photograph)
gore Figure 13 Pit 13 - formation on south and west sides; shows roof of clay at eight feet below surface and below it fossil bearing matrix down to 134 feet here. (Los Angeles County Museum Photograph) 37
Chart VII Shows extent of excavations in Pit 13. (Los Angeles County Museum Photograph) 38
ten feet it was noted that "matrix continues of the same ideal sort as
formerly, but quantities of brush large. "
Botanical aspects of Pit 50: The excavation of Pit 50 was made
in the lake. Although plagued continually with water seeping into
their excavation, they excavated to 25-3/4 feet below the water level
of the lake. At approximately seven feet, which was two feet below
the lake bottom, a rock-like layer of asphaltum was encountered.
Below this layer, three feet under the bottom of the, lake, an almost per- fect tooth of an elephant and a piece of tree trunk was found protruding up through a soft sandy matrix, No other animal or vegetable remains were excavated.
Botanical aspects of Pit 60: In the excavation of this pit many bones were encountered at all depths, but the only plants were noted in D-2 at 14-16-foot depth. Here occasional twigs were encountered with a great quantity of bird material.
Botanical aspects of Pit 61: This pit was considered impor- tant because of fine mammal specimens it contained. Throughout the extensive notes only brief mention of plants appeared. In Sec- tions E and F, at a depth of 171 feet, what seemed to be the remains of some sort of grass or grass roots "similar to Bermuda grass" were encountered. This material was scattered over about a square yard embedded in oxidized asphaltum to a depth of about two feet.
Again, in Section B-10 at about 20 feet, streaks of earth bearing 39
what appeared to be grass roots were encountered.
In Section C-16 at 9 feet, a big mass of rotted twigs and soft
vegetation was encountered. Also, in this same section, a pocket of
small seeds, like those of mustard in size and shape, was encoun-
tered at a depth of 171 feet. There were nearly a half pint of these
in a volume of six cubic inches, and the bulk of them were in a solid
mass.
Pit 61 had been a series of connected pockets, varying in
size from a cubic area of about half a yard to ten yards or more,
rather than one continuous deposit as in Pits 3, 4, 9, etc. Nowhere
did any of the pockets extend below 20 feet; in general these were
exhausted at approximately 18 feet.
Pit 67 adjoined Pit 61 on its northeast side. Although no plant materials were reported in Pit 67, a number of specimens have been extracted from matrix removed from skull cavities.
Figure 14 shows view of Pit 61 and Pit 67.
Botanical aspects of Pit 73: At a depth of two feet below the surface the excavators struck a brown clay bearing some oil and much water. At six feet they encountered a mass of wood, very soft and full of water. This mass extended to eight feet; the last two feet were in an oily, gummy mixture of earth and clay, abso- lutely barren of bones but carrying considerable small vegetation in addition to the wood. The excavation was discontinued at this 4 0 41 point because no bone was found.
Aside from Pit 73, Pits 68 through 100 either held fossil bones or there was no fossil-bearing matrix encountered. No mention, whatever, was made of any plant material having been found in them.
In Pit 81, however, plant material was recovered from matrix re- moved from inside a number of skull cavities. This pit, composed of a funnel-shaped deposit, was excavated to approximately ten feet be- low the 174-foot datum.
Pit 101 and Pit A were excavations made between 1929 and 1950.
Considerable plant material was extracted from the matrix of these pits, however, the quadrat method apparently was not used, nor were data recorded for depth of excavated material. Many kinds of fruits and seeds have been removed from the extracted material. Among these have been the greatest number of juniper seeds found in any of the pits.
Pits B, C, and D will not be included here because of some question about the method used in their excavation. 42
MODE OF DEPOSITION AND AGE
At the time the excavations for fossils began, Rancho La Brea was a tract of land, embracing over two thousand acres, lying to the south at the base of the Santa Monica Mountains. These mountains, which have a general east-west axis, extend eastward for about nine miles from the Rancho La Brea area. The Los Angeles River wends its way eastward along the north side of the Santa Monica Moun- tains for about ten miles, then, at the eastern tip of this Range, it turns and goes south to southeast toward the ocean. The highest ele- vation of the Santa Monica Mountains directly north of the deposits is
1,000 feet, decreasing a little eastward, then rising again to 1,000 feet at its eastern end.
The terrain is of a low plains type with an elevation of approxi- mately 174 feet above sea level at about the center of the deposit.
Springs occurred in the area and water was encountered a few feet be- low the surface in some of the pits.
The elevation rises to 250 feet a short distance to the north of the deposits. This elevation is in an east-west direction, which ex- tends a short distance to the west of the pits and east for about six miles; then, within about a mile of the principal part of Los Angeles, the 250-foot elevation bends southward for about four miles, forming a series of low hills between the Rancho La Brea deposits and the Los 43
Angeles River, which bounds the City on the east.
The Rancho La Brea deposits are at the margin of one of a number of alluvial fans that occur along the south slope of the Santa
Monica Mountains. Below this is an older Pleistocene alluvium com- posed of sand, clay, rubble, and asphalt, overlying Pliocene and
Miocene formations composed of sandy-clay, gravel, sand, and oil - bearing sand. Stock (75, p. 18) made test borings in 87 locations in these deposits. These tests extended to a depth of 30 to 40 feet. He found below soil and fill there occurred yellow clay, frequently asso- ciated with brown clay and oil stained sand. Below this, occasionally within the upper ten feet but almost always below the 10-foot level, there occurred a blue to greenish-blue clay extending down from a few feet to as much as ten feet in thickness. At the lower level, the blue clay is often associated with bituminous material and permeated by seams of tar.
It was first thought that the asphalt bearing pipes, fissures, or chimneys were originally caused by earthquakes, but it is now known that these are caused by the tremendous pressures of gas or oil forc- ing its way to the surface from below. Even today, after a number of the pits have been closed and filled, the tar, gas or oil forces its way out at another point. Of necessity, to prevent undesirable occur- rences of tar pools, several pools are left open to provide vents for escaping gas. 44
During the Pleistocene, the exudation of tar, oil, and perhaps water along with it was much more extensive than at the present time.
The pools of oil were formed in the natural depressions in the irregu-
lar land surface of the area. Most of these pools, which became
areas of deposition, occurred on a northwest-southeast direction
through the primary area of the deposits.
A number of paleontologists have presented various theories
concerning the mode of deposition. The mode of deposition by entrap-
ment was favored by most of the writers [Lytle (48, p. 23), Mathews
(55, p. 47), Merriam (58, p. 475), Rowell (65, p. 10), Stock (75, p.
21), et al. , but based on evidence of some of the material in these
pits, Gilbert (28, p. 63) ventured that the deposition came about by
the drift method. Owing to the amount of fossil material in some of
the pits, this mode of deposition would seem inconceivable for, in
order to account for the quantities of bone material to have drifted in-
to the pits, the area would have had to be covered with many dead and
decaying animals. Stock (72, p. 4), in accounting for the markings on
some of the skeletal elements, attributes these to gnawing and break-
ing by carnivors in their effort to devour trapped animals before en-
tombment. He also accounts for the weathered condition of some of
the bones to have occurred, in part, during the time before the skele-
ton was completely entombed.
Whatever mode is assumed for the deposition of the animals 45
found in these deposits, the fossil plants found therein must have been
growing very near to the pools of tar or within a few miles to the north
of them, and floated into depressed areas by rain run-off from the
foothills. That the deposition did not take place in one span of years
in the Pleistocene is shown by the thick layers of clay in Pit 9 (p. 30,
and Figure 10) and Pit 13 (p. 35 , and Figure 13) that occurred above
the mass of fossil material. The evidence of the tree in Pit 3 found with its roots in situ in a clay bank twelve feet below the surface also
gives some indication of the alluvial buildup that occurred in the area
from the time deposition first began in this pit until today. Gilbert, however, believed (27, p. 51) that this alluvial buildup was much greater before it became a plain of erosion and that the alluvium had eroded away and uncovered the deposits.
The age of the Rancho La Brea deposits has been variously given as ranging from early to late Pleistocene, but nearly all the paleontolo- gists working on the faunal assemblage in these deposits are now con- vinced that it is late Pleistocene. Based on the date of extinction of the large Falconiformes, Howard (34, p. 88) placed the age of the
Rancho La Brea deposits as the middle or the early part of the late
Pleistocene. She later placed the age at the latter part of the late
Pleistocene (35, p. 714).
A core was taken from the trunk of the tree removed from Pit
3 (p. 14, and Figure 3) and a portion sent to two institutions for 46 radiocarbon dating. Stuiver et al. (76, p. 59) at Yale University got a measurement of 15, 400 + 300 years in the untreated material; another portion of this core was treated with xylol to remove the tar and the measurement, then, for the treated material was 13, 890 + 280 years.
Hubbs et al. (37, p. 210 and 214) at Scripps Institute of Oceanography got a measurement of 14, 400 + 300 years on the treated material, and a measurement of 28, 000 years on the tar extracted from the wood
sample. The significance of these dates, reported by Howard (35, p.
714), indicates that a relatively short span of years was involved in the transition between the typical Pleistocene fauna in the Pit 3 and that of today.
The rich fauna of the Rancho La Brea deposits has always been
regarded as interglacial; the specific interglacial, however, has not been determined. The recent opinion places the Rancho La Brea beds
in the Sangamon interglacial (23, p. 304). The duration of the Pleis-
tocene, estimated at one million years by the radioactivity methods,
is considered to be well within the limits suggested by geological pro-
cesses and the relative evolution of life. The Holocene (Recent) is
believed to have lasted 10, 000 to 20, 000 years according to how it is
delimited from the Pleistocene (84, p. 349).
From this, it would appear that there is some question as to whether the tree and other paleontological material found in Pit 3 is of
Pleistocene or of Holocene age. If the Holocene lasted 10, 000 years 47 then this material would be considered very late Pleistocene; but if the
Holocene lasted up to 20, 000 years, then the material from Pit 3 may be early Holocene.
One can scarcely arrive at an exact age for the Rancho La Brea deposits based on the delineations of the botanical material being re-
ported herein. When all available paleobotanical material has been
studied, identified, and close correlations made, not only with ma terial from each pit but with other Pleistocene localities, with geolo-
gical processes, and with the processes of botanical evolution, one
can then evaluate the data to arrive at a more exact age. 48
MATERIALS AND METHODS
Except the material from Pit A, most of the matrix used as
source material came from inside of skulls of sabre-toothed cats and other animals. In most instances, these skeletons bore data as to pit number, section of pit, and depth at which each was excavated.
More reliable interpretation can therefore be made on the plant ma- terial extracted from these matrices than from matrix from an un- known depth.
The crude matrix was put in pans of kerosene and left until dis-
solved. The residue was carefully retained by filtration and fresh kerosene added to the pans, then again allowed to stand until more
asphaltum was dissolved from the material. Careful rocking of the
pans hastened the extraction. This was repeated several times until
the solution became somewhat clear, filtering after each washing so
as not to lose even the smallest specimen.
The material was then run through several baths of xylol to re-
move the kerosene and any minute traces of asphaltum still remaining
in the material. The extracted material was then placed in trays and
allowed to air-dry until all traces of liquid had evaporated. The re-
sulting matrix would be in a fine to coarse friable condition with all
particles free from each other,
The Soxhlet method, using toluene as the solvent, was used but 49 this method was discontinued because it was considered too dangerous,
Then began the tedious task of sorting the fossil material from the dry, sandy matrix. In order to separate the fossiliferous materi-
al from the sand, gravel, and silt, first the dry matrix was sifted through three geologists sieves in sizes of 3 mm. , 2mm. , and 1 mm.
This gave separations in four sizes. The material that passed through the 1 mm. sieve was mostly fine silt and particles less than 1 mm. in
diameter. This was checked for microscopic seeds. The material that remained in the 1 mm. sieve is smaller than 2 mm. and larger than 1 mm. and was checked for small seeds. These were removed and the remaining material was stored with data for future study.
In each of the other two sieves (No. 2 mm, and No. 3 mm. ) the ani- mal bones, insect parts, and recognizable plant parts -- wood, twigs, leaves (mostly fragments), fruits, seeds, etc, -- were sorted out and the remaining matrix stored. The animal material was then
separated from the plant material. The plant material was sorted and classified into morphological categories of wood, bark, stems, and twigs, leaves and leaf fragments, fruits, seeds, and other recog- nizable parts. Since this study was particularly concerned with fruits and seeds, special attention was given, during the sorting, to grouping together of seeds and fruits having similar form and mor- phological characteristics. Since all fossil material from these de- posits have a blackish appearance, even after the asphaltum had been 52 revealed a similar paucity of information. A random sampling of several California floras first revealed these facts. Then it was de- cided to make a survey of several taxonomic floras in order to deter- mine to what extent the descriptions of fruit and seeds were generally omitted from the delineations of orders and families.
For this survey, Families of Dicotyledons by Alfred Gunderson
(1950), Families of Flowering Plants: Dicotyledons by J. Hutchinson
(1926), and Manual of Flowering Plants of California by W. L. Jepson
(1925) were used. The latter text is primarily concerned with the flora of the region involved in the fossil study.
The survey covered only the dicotyledonous families in these
references. Of the number of families dealt with, only 110 occur in
California. Suffice it to say that this survey revealed much diverse opinion as to the morphology of the fruit and seed or the term applied to its structure in many cases, and scarcely no external features were described that would help to identify them.
From the results of this survey, it was concluded that floras
or manuals dealing with taxonomic and morphological characters of plants could not be relied upon to furnish information for the delinea- tion of the fossil fruits and seeds, It became necessary, then, to
rely wholly or almost entirely on searching through collections in herbaria and making collections in the field to find fruits and seeds
comparable to the fossils. Also, not only were comparisons made 53 between the modern material and the fossil specimens, but compar-
isons were made between species in a given genus in order to ascer-
tain the one species more nearly resembling the fossils from among those of the remaining members in the genus. 54
SYSTEMATIC DESCRIPTIONS
Many collections of fruits and seeds were made in the field for
comparison with the fossil material. Several thousand specimens, particularly those with mature fruits and seeds, were studied in her- baria of the Los Angeles County Museum, Oregon State University,
Rancho Santa Ana Botanic Garden, University of California at Berkeley,
and University of California at Los Angeles.
Many literature references were used to corroborate identifica- tions and to prepare descriptions of the modern counterparts. The
following were particularly useful: manuals on floras by Abrams
(1, 2, 3), Abrams and Ferris (4), Jepson (44), Mason (50), and
Munz (58); manuals on trees and shrubs by Benson (6), Dallimore and
Jackson (18), Greguss (29), Harlow (30), Jepson (39), Little (43),
McMinn (52), Sargent (66, 67, 68, 69), Stanley (71), Sudworth (77),
Vines (82), and U. S. Dept. of Agriculture (80); books, manuals, and
pamphlets on seeds by Beijerinck (5), Brouwer and Stahlin. (9), Col- bry (15), Gaertner (25), Herron (32), Iseley (38), Kelley (41), Martin
(45), Musil (59, 60), and U. S. Dept. of Agriculture (79, 81).
Reports on Pleistocene floras in California and other paleo- botanical papers were studied to acquaint myself with records of
Pleistocene species in the literature. The following are important
sources: Chaney (10, 11), Chaney and Mason (12, 13), Frost (24), 55
Knowlton (42), Mason (46, 47, 48, 49), and Potbury (64).
The only work pertaining to the Pleistocene flora of Rancho La
Brea deposits was that of Frost (24) in which six species were re- ported and one unidentified stem of a Compositae was mentioned. The recorded species are: Pinus tuberculata Gord., Cupressus macro- carpa Hartw., Juniperus californica Carr. var, breaensis n. var. ,
Quercus agrifolia Nee, Celtis mississippiensis Bosc. var. reticulata
Sarg., and Sambucus glauca Nutt.
Fossil material representing all but one genus, Celtis, is in- cluded in the following systematic descriptions. Discussion of these and their reassignment, synonymy, or problems of taxonomy will oc- cur under the respective species, Celtis mississippiensis var, reti- culata, which Frost cites as occurring in Pit 7, was described but not illustrated. The description he gives of this specimen, which consisted of one seed, does not fit the description of, or the appear- ance of any "hackberry" seeds studied. None of the material upon which Frost did his study for this report has been located in the her- barium or the Geology Department of the University of California where his work was done. In his description of the Celtis specimen, a number of seeds found in these deposits are described that do not belong to Celtis. These particular seeds have not as yet been de- termined.
One other paper concerned with the fossil flora of the Rancho 56
La Brea deposits is that by Templeton (78) in which a brief account of the excavations, the species reported, and the problems to be en- countered in further studies was reported.
The following systematic account of the fossil fruits and seeds of the Rancho La Brea deposits records the scientific determinations of only a portion of the more than 4, 000 specimens separated from the matrices of several pits. Before further work can be done, it will be essential to acquire a complete authenticated reference col- lection of modern fruits and seeds.
In all cases, except where otherwise indicated, the names used for the fossil plants are those used in the floras for the modern coun- terparts. Controversial taxonomic problems and details of synonymy, which seemed to be beyond the scope of this paper, have not been dis- cussed. Maps showing the range of the modern species involved in the respective fossils were made from data derived from the study of actual herbarium specimens. Some species having a cosmopolitan distribution or insufficient herbarium records available to account for known distribution, were not mapped. The maps were prepared to show proximity of the modern species, to the fossil deposit.
PINACEAE Family
Pinus L.
Three cones belonging to the closed-cone pine group occurred in one of the pits in the Rancho La Brea deposits. One cone was 59 Figure 15 a. Pinus muricata, two cones, side view; from Purissima Hills near Lompoc, California. The smaller cone has the size and characters of most of the cones studied in this species; the larger cone is that of the Pinus sp. in question. 1/2 x. b. Pinus muricata, close-up of ventral side of smaller cone above. 2/3 x. 60
7 61
Pinus attenuata Lem.: More than 150 cones of this species were studied. These represented several stations in each of the fol- lowing areas: Glenn County, Siskiyou County, Shasta County, Nevada
County, Del Norte County, Humboldt County, Napa County, Placer
County, Mariposa County, Santa Cruz County, Monterey County, San
Luis Obispo County, San Bernardino County, and Orange County.
In most cases, the cones were closed. Nearly all the cones are narrow-ovoid, asymmetrical, and light golden brown in color.
They range in size from 8 cm. to 14 cm. long. The scales on the dorsal and ventral sides are comparatively fewer per square inch than in the preceding species. All of the scales on the dorsal side have apophyses with enlarged umbos that are low, broad, and pyra- midal in form, occasionally enlarging to a somewhat angular pointed knob on the scales near the stem end. The dorsal apophyses varied from 20 mm. at the stem end to 12 mm. toward the apex in some
specimens, but in most specimens the apophyses, on the horizontal axis, are all about the same size, 15 mm. in the smaller cones to
20 mm. in the larger cones. The scales on the ventral sides have apophyses that are large, broad, and flat. These are from 10 to 15 mm, broad on their horizontal axis, with the larger size occurring midway between the stem and apex in some of the specimens, while in many cones the ventral apophyses are about equal in size, about
15 mm. from stem to apex (Figure 16, a., b., c.). 62 Figure 16
Pinus attenuata 1,6mmon
A form of cone commonly found in conifer collections. a. Side view b. Dorsal view c. Ventral view