Paleoneurology 1804–1966: An Annotated Bibliography

256 Pages·1975·20.541 MB·English

by  Dr. Tilly Edinger (auth.)

Advances in Anatomy, Embryology and Cell Biology
Ergebnisse der Anatomie und Entwicklungsgeschichte
Revues d'anatomie et de morphologie experimenLale
49/1-6
Editors
A. Brodal, Oslo' W. Hild, Galveston' J. van LimlJoryh, Amsterdam
R. Ortmann, Koln· T. H. Schiebler, Wurzbury·G. TOndury, Zurich·E. Wolff. Paris
Tilly Edinger
Paleoneurology 1804-1966
An Annotated Bibliography
Springer-Verlag Berlin Heidelberg New York 1975
t
Dr. Tilly Edinger
Museum of Oomparative Zoology
Harvard University
OamlJridge/Mass. 02138
U.S.A.
ISBN-13:978-3-540-07060-3 e-ISBN-13:978-3-642-66029-0
DOl: 10.1007/978-3-642-66029-0
Library of Congress Cataloging in Publication Data. Edinger, Tilly, 1897-1967. Paleoneurology 1804-1966. (Ad
vances In anatomy, embryology, and cell biology; v. (9) Bibliography: p. Includes Index. 1. Vertebrates,
Fossil-Bibliography. 2. BraIn-Evolutlon-Bibliography I. Title. II. Series. [DNLM: 1. Brain-Bibliography.
2. Evolution-Bibliography. 3. Paleontology-Bibliography. Wl AD433k v. 49/ZWL300 E23p 1804-1966]
QL801.E67 vol. 49 [Z6033.P2] [QE841] 574.4'08s [016.566] 75-12819
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Contents
Foreword (by Bryan Patterson). 7
General Catalogue . . . . . . 12
Appendix: Hominidae Catalogue 183
Systematic Index (by Joan Echols) 235
Foreword
Dr. Tilly Edinger's first published paper dealt with a brain cast-in more
exact terms an endocast of the cranial cavity-of Noth08auru8, a Triassic relative
of the plesiosaurs. With this she embarked on a working lifetime of devotion to
paleoneurology, a field of study that she was to transform. A daughter of the
famous neurologist Ludwig Edinger, it was appropriate as well as fortunate that
her early interest in fossil vertebrates should have become focused upon the
recovery of such information concerning the history of the central nervous system
as could be obtained from fossil material. Her father evidently had no direct
influence upon her choice of· this then obscure and difficult subject, although
within the family circle she presumably absorbed from him some appreciation of
neoneurology. Indirectly, however, through his accumulation in Frankfurt of an
outstanding collection of recent brains, he provided the comparative material
essential to her studies during the years she spent there.
Early in her career she published Die FOBsilen Gehirne (1929). Here was
gathered together for the first time nearly all the widely scattered information
on the topic. It had an immediate effect. As one author justly remarked, this
"invaluable review ... serves not only as a basis for continuing and systematizing
research on brain casts but also as an indication of the more serious gaps in present
knowledge" (Simpson, 1933). The bibliography appended to it listed 250 titles.
A bibliography she published in 1937 included 160 additional titles. Some of
these were older papers that she had not previously encountered but 115 of
them-a number equal to nearly half of the total listed in Die FOBsilen Gehirne
had appeared in less than a decade after pUblication of that work. It may fairly
be claimed that many, perhaps a majority, of these had been inspired in one way
or another by it. The groundwork for a science of paleoneurology had been laid.
During the decade that followed, the political situation in Germany made life
increasingly difficult for her, although she continued to work and publish. The
most interesting of her papers during this period dealt with sirenian brain casts
(1933). She was able to show that the brain in this order, while increasing some
what in size, had changed very little in form from the late Eocene to the present.
This study, the first demonstration of an evolutionary series, however incomplete,
over a very long stretch of time, might have served as a basis for erroneous con
clusions as to the general course of brain evolution in the Mammalia had it con
tinued to stand alone. It was to be superseded by a truly revolutionary study,
one that was to bring paleoneurology into a new dimension.
Fortunately for herself and for science Dr. Edinger was able to leave Germany
in 1939 and to come to the Museum of Comparative Zoology in 1940. There she
began work on a project that she had long believed should be carried out, a
study of the history of the brain in the horse family from the then time of earliest
appearance in the fossil record to the present. Published in 1948, the findings were
spectacular: the brain of the early Eocene eohippus proved to be approximately
on a level with that of Didelphis, one of the most primitive of living mammals,
advances in brain structure, like those in other organs, had not proceeded at a
constant rate within the family but had varied in tempo, the olfactory sense in
7
horses had not diminished in the course of time, and so on. The specializations
achieved between eohippus and Equus had taken place after the family had be
come distinct from others in the order Perissodactyla, and it followed from this,
since most of the major groups of mammals were in existance by Eocene time,
that a very great deal of parallel and convergent evolution in brain structure
has gone on, particularly as regards the neocortical and neocerebellar areas. At
a stroke, in fact, it had become obvious that the scala naturae approach to brain
evolution could not be expected to reveal the history of events. In Die Fossilen
Gehirne (p. 81), in agreement with an almost forgotten suggestion by Turner (J.
Anat. Physiol., 25, p. 153, 1890), she had remarked "die Gyrifizierung also augen
scheinlich in jeder Ordnung unabhangig entwickelt wird." Here was 'proof; she
could now (1949, p. 21) state with confidence that "the material of paleoneurology
demonstrates that the material of comparative anatomy, the series of extant
brains, is not capable of revealing the actual courses of evolution which have
resulted in these existing types."
Evolution of the horse brain provided a standard against which much could be
judged!. Looking back in time from the cerebra of eohippus and of the con
temporary condylarth Phenacodus it became possible for her to interpret small
protuberances on the otherwise smooth cerebra of Paleocene ungulates as being
neopallial in nature (1956b, p. 19). The few known Mesozoic mammalian brain
casts show nothing comparable to these little hillocks nor any suggestion of a
rhinal fissure, from which (1964 b, p. 14) "one must conclude that non-olfactory
cortex can hardly have been developed beyond the inherited 'primordium neo
palii'." The neopallium, that hallmark of living Mammalia, did not make its
appearance until long after the origin of the class, and its major elaborations
were Cenozoic events. As regards neopallial specialization mammalian groups
have varied widely. Some, including highly successful surviving ones, have under
gone little. The horses are a group in which a good deal of advance went on
throughout Tertiary time, others, such as camels, are more or less comparable
to them in this respect, while yet others, cetaceans, elephants, hominids, have
gone far beyond them. Early specialization was no guarantee of further progress.
The early Eocene anaptomorphid prosimian Tetonius had the most advanced
brain so far known for its time; its living relative Tarsius has one no different
in essentials. Neocortical specialization went on at different rates even among
closely related families. Palaeotheres and titanotheres, both of which became
extinct in the Oligocene, were more advanced by that time than the contemporary
M esohippus.
Dr. Edinger took careful note of all this, and of more besides, and drew a
bead (especially 1962a) on the hypotheses of O. C. Marsh, who in the 1870's and
80's had set forth various propositions under what he termed the "general law
of brain growth." His views were based on quite insufficient evidence and were
only partially correct, but they had a very pervasive influence and some of his
more spectacular errors have been repeated ad nauseam. Their influence, she
1 Since this was written it has been reported (Soc. Vert. Pal. News Bull., no. 100, 1974,
p. to) that L. Radinsky has "prepared an endocranial cast of Hyrawtherium that is signifi
cantly more advanced than the specimen figured by Edinger in her monograph on the evolution
of the horse brain; this suggests that Edinger's specimen was not from a perissodactyl."
Dr. Edinger did consider this possibility, but decided against it on the evidence available
at the time. Her conclusions as to the very rapid early evolution of the equid brain may thus
require modification, but the rest of her views on the subject should not be affected.
8
believed, was due to their fitting in with the thinking of many neoneurologists
in whose eyes the brain, and especially the neopallium, would naturally be the
all important organ of the body. By her forceful presentation of the facts revealed
by paleoneurology and by the very uneven levels of neopallial development
exhibited by living mammals she placed the brain in proper perspective by
implicitly stressing that it is simply one organ among the many on which
evolution can act in various ways, and that specialization of it was not by any
means the only road to evolutionary success. Unfortunately, having done this
she went further and came in the end to question whether a specialized brain was
of any advantage at all. In one of her last papers (1965) she-made the following
remarkable statement: "The series [of camelid braincasts] also testifies against
the concept that a brain thus advanced is an advantage in natural selection.
Extinct in North America where they flourished for some 40 million years, wild
Camelids now exist only in small areas of two other continents." As if advances
in brain structure had not been selectively advantageous to camels during
their 40 million year occupancy of the North American continent and as if a
specialized brain, any more than specialized teeth or feet, should if really
adaptive ensure a lineage possessing it against decline or extinction. In fact the
statement is not one that a person familiar with current evolutionary thinking
would be at all likely to make. And for this there is, I think, an explanation.
During her lehrjahre there was no generally accepted body of evolutinary
theory. Biologists agreed on the fact of evolution but not on much more; represen
tatives of the disciplines involved were at swords' points and confusion reigned.
Under these circumstances most people simply went on with their work while
waiting for the dust to settle. As she passed into her meisterjahre she came to
suffer increasingly from a form of deafness for which a hearing aid did not ade
quately compensate. This she kept turned off much of the time, switching it on
for purposes of conversation. And a conversation with her could be as taxing as
it was fascinating. She would start to pursue a main topic, branch off to deal
with a secondary one, perhaps branch off again from that to take up a tertiary
one, exhaust this and return to the secondary, exhaust that and at last get back
to the main track, often repeating the process once or twice more before reaching
the end. Her listeners while following these discussions within discussions had also
to keep the branching points firmly in mind if they were not to become lost. Once
this key to her discourse was grasped her expositions could be followed but-and
this is the point-it was largely one way communication. To venture intruding
upon and breaking the thread of these conversational arabesques seemed almost
improper; comments and queries that came to a listener's mind as she talked
remained all too often unspoken. She was thus progressively cut off from the
give and take that is so pleasant and useful a part of scientific life and which
helps so much in the formulation and testing of ideas. Her affliction was already
far advanced by the time that a synthesis was being hammered out in evolutionary
theory. Absorbed as she was in her own investigations, much of this work may
simply have passed by her unnoticed. She did not, at any rate, look at brain
evolution in terms of the theory; had she done so I believe that aspects of it she
found puzzling might have been clearer to her.
Paleoneurology, as Dr. Edinger repeatedly stressed is just getting into its
stride and an enormous amount of work lies ahead. There are whole orders, even
of mammals, for which not one braincast is known. ("May this bibliography make
9
my colleagues aware of the ... gaps to be filled merely by having endocasts made
of the crania in their collections.") Even for the Equidae, the best evolutionary
sequence yet available, only a good outline is so far in hand and a great deal
remains to be learned. Other lineages demand investigation. It would be inter
esting for example to know when the cerebrum began to enlarge markedly in the
Cetacea and the Proboscidea, and if the increases were gradual or initially rapid.
A fascinating and wide open area of investigation lies in searching for clues to the
times of origin of aspects of behavior, particularly behavior of what may be
called the bread and butter kind-the ways in which animals cope with and
make a living in the environments to which they are adapted-rather than of
the more spectacular sorts-courtship, agonistic and the like-that' engage so
much of the attention, of behaviorists. Behavior of this basic sort is intimately
correlated with structure and function and may be reflected in the gross morphol
ogy and surface details of the br8.in.. A case in point-an obvious one-is provided
by the pterosaurs. From braincast evidence alone (Edinger, 1927, 1941) it should
have been quite clear that these reptiles were fully capable of sustained flight, the
long-tailed rhamphorhynchoids of stable, the short-tailed pterodactyloids of the
more demanding unstable flight (cf. J. M. Smith, 1952). The-braincast of Archaeo
pteryx, especially as reinterpreted by Jerison (Nature, 219, p. 1381, 1968), is
consistent with the adaptations to stable flight shown by the skeleton and
feathers. Continued progreBB in electrophysiological mapping should enable much
progreBS to be made in tracing back somatic sensory specializations in various
lineages. The problems and the possibilities flow on from the thresold to which
Dr. Edinger has conducted us.
Dr. Edinger had at one time hoped to round out her life's work with a modern
ized version of Die Fossilen Gehime. To this end she kept up to date her ever
growing card file of the literature and began a catalogue of the known fossil brain
casts. By one of life's ironies, however, she had wrought too well; the field she
had revivified in 1929 had grown during the intervening years to an extent such
that a work of comparable scope would have required many years for its com
pletio~. Besides, she came to feel (MS, 1961), "there is now such an expansion of
aspects and also of material, and of literature ... that the situation is just too
fluid ... to write a book about it all." Accordingly, she decided to concentrate
first on completing the annotations to the bibliography, publish that and then go
on to the catalogue. Fate in the shape of a fatal accident intervened but fortu
nately the bibliography could be brought into order for publication. It is here
presented and is the last contribution we shall receive from her. She had planned
an extensive Introduction for which four slim notebooks are among her effects.
I have repeatedly but without SUCceBB gone through these in the hope of re
constructing what she had intended to write. The entries in them consist of
jottings, in part mnemonic, that would have served only their author as the
skeleton for a narrative; they cannot do so for another.
The bibliography records a nearly six-fold increase of literature on the subject
over the combined lists of 1929 and 1937. This "is mainly the result of the recent
increase in the field, but it is also due to the inclusion of older literature that I
had not previously seen and of works of a general nature, such as textbooks,
that contain original remarks on fossil brains and/or figures copied from other
pUblications. All this should make the bibliography a historical record of paleoneur
ogy, reflecting both its spread and the changing attitudes toward the value of
10
endocranial casts." The annotations refer strictly to paleoneurological content
and therefore "[I must] warn that necessarily partial quotations may give a
wrong impression. Picking [out] only data about and comments on paleoneurology
is not an abstract of the entire publication, nor can brief quotes contain all of
an author's ideas." Papers that she believed to contain errors of one sort or
another tend to be disproportionately annotated. Somewhat paradoxically there
fore" it is the best, the entirely reliable papers, which are listed with the briefest
annotations-a mere pointing out that unobjectionable descriptions exist." Some
contributions may have been missed: "much to my regret, papers published
entirely in non-Latin alphabets, although I suspect they-contain paleoneuro
logical data, have been passed over unless they contained figures of endocranial
casts." In the course of her work she came across numerous references that might
have been expected from the titles to discuss paleoneurology yet made no mention
of it at all. In her notebooks she laments the time spent on these, but readers
will nonetheless be grateful for the trouble taken over them. If an alluring title,
such as "Phylogeny of the avian brain," does not occur in the bibliography it
is a rather safe bet that, however interesting otherwise, the paper contains
nothing paleoneurological.
A large part of the literature on fossil hominid brain casts is, she felt, "utterly
different from that on brains of extinct animals, which is anatomical"; much of
it is "not really brain anatomy, except for [attempted] tracing of this or that
sulcus-for which hominid endocasts, particularly those made with methods now
obsolete, are most unsuitable objects." In one notebook she quotes with approval
von Bonin's stricture (1963, p. 41) that "much that we have gathered from the
literature is of little value, since it is based on mistaken premises and homologies
which can hardly be expected to survive a more critical examination." In defer
ence to her wishes nearly all the hominid literature is set apart and is not indexed.
Here and there through the notebooks are scattered sorrowful entries com
menting on discussions by some neoneurologists-even in the 1960's--of brain
evolution based on series of living forms, and indignant ones castigating yet
another repetition of one of Marsh's more sensational errors. For an end to such
things we can look with confidence to the passage of time.
Support for the preparation of the bibliography and of other work was pro
vided her by the Milton Fund of Harvard University, the American Association
of University Women, the American Philosophical Society and the National
Science Foundation through Grants GB 1364 and G 23566. Aid was received
from numerous individuals over the years; grateful acknowledgment is due to
Dr. Joan Echols for the preparation of the Index to the General Catalogue, to
her and to Dr. Clayton E. Ray for aid on the annotations, to Mrs. Eleanor Adam
Gossen, Mrs. Donna Ray, Mr. Dean Smith and Mrs. B. Gail Browne for typing
and checking, and to Mrs. Browne for final arranging and editing.
It was Dr. Edinger's hope that this work would give renewed impetus to the
subject she loved; this will surely prove to be the case.
Museum of Comparative Zoology, Harvard University Bryan Patterson
September, 1970
Papers cited in the foregoing by year only may be found in the bibliography. Quotations
without indication of source have been taken from the notebooks. For obituary notices of
Dr. Edinger see: H. Hofer (Morph. Jahrb., 113, pp. 303-313,1969), A. S. Romer (News Bull.
Soc. Vert. Pal., no. 81, pp. 51-53, 1967) and H. Tobien (Palaont. Zeitsch., 42, pp. 1-2, 1968).
II
General Catalogue
Abel, 0.: Grundziige der Palaeobiologie der Wirbeltiere. Stuttgart. 1912. [No brains men
tioned.] In: "Special Adaptations to Life in Water", "The parietal organ" (pp. 463-465),
enlarging upon Dollo 1905, finds that, as for example in Plioplatecarpus, the parietal
organ "was best developed in those vertebrates whose eyes lie on the upper surface of the
head" [which would exclude, e.g., therapsids!] "Likewise enigmatic is the physiological
significance of the hypophysial foramen in ichthyosaurs (figs. 357, 358)" [from Broili 1909,
with the respective opening labelled in the ventral view, "Austrittsstelle der Hypophyse"!]
Abel, 0.: Die eocanen Sirenen der Mittelmeerregion. Erster Teil: Der Schadel von Eotherium
aegyptiacum. Palaeontogr. 09, 289-360 (1963). pp. 350-351, "The Brain", uses three
natural endocasts; pI. XXX, fs. 1, 5; pI. XXXII, f. 6; pI. XXXIII, fs. 3-5; detailed de
scription of last specimen in legend
Abel, 0.: Vorgeschichte der Cetaceen. Pp. 395-410, in Weber, 1928 a. P. 399, brain of Zeuglodon;
notes retention of large olfactory nerve
Abel, 0.: Embrithopoda. Pp. 440-445 in Weber, 1928b. P. 441, "The volume ofthe braincase
is larger than in the amblypods." Fig. 273, A-C, Arsinoitherium brain, after Andrews
1906
Abel, 0.: Vorgeschichte der Sirenia. P.469-504 in Weber, 1928c. P. 497, Eotherium, known
first only by an endocranial cast. Fig. 326, otic region and endocranial cast, lateral, after
Abel 1912
Abel, 0.: Amblypoda. Pp. 690-695 in Weber, 1928d. P. 693, brain of Uintatherium extraordi
narily small
Abel, 0.: Saugetiere (Palaontologie). Handworterb. Naturwiss., 2nd ed., 8, 859-944, 1933.
In general part lists, among" Some of the most important specializations in the course
of phylogeny of the mammals": "brain capsule small, narrow~brain capsule broad,
vaulted" (p. 862). In systematic part, introduction to Carnivora contains a paragraph
entitled "The Specialization of the Brain of the Carnivores": "The oldest Carnivora
(e.g., Arotooyon and Triisodon of the Paleocene, Didymictis and Sinopa of the Lower
Eocene) had a small, little specialized brain whose evolutionary level is comparable to
that of marsupials. In the course of Tertiary times there occurs, independently in the dif
ferent branches, a conspicuous specialization and size increase of the brain" (p. 883).
[Otherwise, this extensive memoir takes no notice of brain structure, nor post-Marshian
literature; it merely re-states and generalizes Marsh's dicta in the following instances:]
The family Elotheriidae is characterized as having a brain cavity "almost reptile-like
small" (p. 920), the Condylarthra as having a very small brain and the cerebellum poste
rior to the smooth cerebrum (p. 921). Brain in skull of Brontotherium is copied from Marsh
"to show the extraordinary smallness of the brain in proportion to the skull" (fig. 112).
"The brain of Goryphodon was extraordinarily small ... Also in the Dinoceratidae the
brain cavity was extremely small" (p. 936)
Agnew, J. D.: Cranio-osteological studies in Dicynodon grimbeeki with special reference to
the sphenethmoid region and cranial kinesis. Palaeont. afro 6, 77-107 (1959). Two serially
sectioned skulls establish that the preparietal forms the anterior border of the parietal
foramen which is "well-developed in both specimens" (p. 85) [its length is almost half the
breadth of the foramen magnum in fig. 34], and the presence of a distinct floccular fossa
(pp. 102, 106, figs. 41-42)
Ahl, E.: Xenopus stromeri Ahl n.sp. Pp. 141-142 in E. Kaiser, ed., Die Diamantenwiiste Siid
westafrikas, 2, Berlin. 1926. All frontoparietals of this presumably Lower Miocene frog
have a small, longitudinally oval foramen close to the anterior end (p. 142, fig. 22). [This
canal, which encloses the connection of Stirnorgan and brain, has since been ascertained
in extant species of Anura; see, e.g. Winterhalter 1931 in Acta zooi. 12, pp. 55-58, and
Griffiths 1954 in Proc. Zooi. Soc. London 123, p. 788.]
Aldinger, H.: tlber einen Eugnathiden aus der unteren Wolgastufe von Ostgronland. Meddei.
om Gremland 86, no. 4, 1-52 (1932). "Brain Cavity and Brain" of Gaturus (pp.21-23)
and its cranial "Vessels and Nerves" (pp.26-30) are described on the basis of sectioned
crania (figs. 3-6) and an "endocranium" (pI. I, f.2) in which some of the natural endo-
12