Larry Poulsen is simply incorrect. Both Schmidt and Mercer clearly stated that burrowing animals DID have an impact on the layers. That is one of the issues I address in this post (which I also posted on the fair video thread which has been discussing horses)
Many thanks to Chris for providing the necessary scans (that was a lot of work!!) and to Runtu who provided his expertise obtained in his Latin American studies and translated the pertinent sections of the Schmidt citation. It appears Sorenson/Peterson was correct in part of his translation, but made serious errors of commission and omission that were obviously designed to strengthen his argument.
First, here’s the reference to the Schmidt findings from Sorenson/Peterson:
Subsequent digging has expanded the evidence for an association of humans with horses. But the full story actually goes back to 1895, when American paleontologist Henry C. Mercer went to Yucatan hoping to find remains of Ice Age man. He visited 29 caves in the hill area—the Puuc—of the peninsula and tried stratigraphic excavation in 10 of them. But the results were confused, and he came away disillusioned. He did find horse bones in three caves (Actun Sayab, Actun Lara, and Chektalen). In terms of their visible characteristics, those bones should have been classified as from the Pleistocene American horse species, then called Equus occidentalis L. However, Mercer decided that since the remains were near the surface, they must actually be from the modern horse, Equus equus, that the Spaniards had brought with them to the New World, and so he reported them as such.3 In 1947 Robert T. Hatt repeated Mercer's activities. He found within Actun Lara and one other cave more remains of the American horse (in his day it was called Equus conversidens), along with bones of other extinct animals. Hatt recommended that any future work concentrate on Loltun Cave, where abundant animal and cultural remains could be seen.4
It took until 1977 before that recommendation bore fruit. Two Mexican archaeologists carried out a project that included a complete survey of the complex system of subterranean cavities (made by underground water that had dissolved the subsurface limestone). They also did stratigraphic excavation in areas in the Loltun complex not previously visited. The pits they excavated revealed a sequence of 16 layers, which they numbered from the surface downward. Bones of extinct animals (including mammoth) appear in the lowest layers.
Pottery and other cultural materials were found in levels VII and above. But in some of those artifact-bearing strata there were horse bones, even in level II. A radiocarbon date for the beginning of VII turned out to be around 1800 BC. The pottery fragments above that would place some portions in the range of at least 900–400 BC and possibly later. The report on this work concludes with the observation that "something went on here that is still difficult to explain." Some archaeologists have suggested that the horse bones were stirred upward from lower to higher levels by the action of tunneling rodents, but they admit that this explanation is not easy to accept. The statement has also been made that paleontologists will not be pleased at the idea that horses survived to such a late date as to be involved with civilized or near-civilized people whose remains are seen in the ceramic-using levels.5 Surprisingly, the Mexican researchers show no awareness of the horse teeth discovered in 1957 by Carnegie Institution scientists Pollock and Ray. (Some uncomfortable scientific facts seem to need rediscovering time and time again.)
Here is Runtu’s translation of the pertinent section from Schmidt:
From page 253:
Critical for associating human industry with pleistocene fauna is layer VIII, where there is no ceramic but where lithic tools and many horse remains appear. But unfortunately there are horse [remains] in layers VII and VI and also a very small quantity in layer V, all three containing ceramics.
Obviously there is some disturbance in these layers. Rodents as well as the most common mammals from the cave stand out in studies of the cave's fauna.
The only radiocarbon dating published (1805 +- 150) BC was taken using a combined sample of various pieces of charcoal and belongs to the area of contact between layers VII and VIII.
The stratigraphic and faunal analyses clearly establish that the excavated sediments must have accumulated from the Pleistocene era to the present, with heavy interference at least from layer VII on up. Only layer VIII remains a possible area of occurrence of both lithic material and pleistocene bones in a primary context. Unfortunately in neither this layer or others is there direct association of human tools with the bones, nor are there homes where charcoal or bones were clearly used or worked. The same is true with layer VII (El Tunel).
pp. 254-55
[After discussing flora found in the cave]. The situation in terms of fauna is more complicated. The majority of the animals discovered are represented since the Pleistocene era, having their origins in some of the neo-arctic and neotropical fauna. Studying in detail only the rodents, a sequence of types of vegetation the caves' surroundings was established that is very similar to that accomplished by means of pollen: layers before XIII-B, grassland; layers XIII and XII-L, medium jungle; layers XII-K to VIII, once again grassland; and from VII to I the current vegetation. These changes were not sudden but rather constitute advances and declines of the jungle with greater or lesser extension of the grasslands, where large animals and certain specialized rodents lived.
Once again the end of pleistocene conditions appears to be situated in the region of layers VIII and VII of the well "El Toro." Of the four extinct pleistocene species (Mammut americanum, Canis diris, Tanupolama, and EQUUs conversidens) and the three whose distribution receded more to the north (Bison bison, Canis lupus, and Canis latrans) five did not occur above layer VIII in "El Toro" and layer VII-F in "El Tunel." The exceptions are the bison with three problematic examples in layer VI of "El Toro" and the horse, with 44 fragments in layers VII, VI, and V (all with ceramics), in "El Toro" and 59 fragments en the subdivisions VII-B and VII-E in "El Tunel." What is clear is that the presence of the horse Equus conversidens alone cannot be sufficient to declare a layer as pleistocene in its entirety, given the long series of combinations of this species with later materials in the collections of Mercer, Hatt, and others. Something happened here that is still difficult to explain. Horse bones seem to have formed the last layer of the Pleistocene or Epi-Pleistocene in various caves, or they must have been dragged into the caves decades up to millenia later, something that is difficult to accept given the climatic conditions of the Tropics. If we postulate a longer survival of the horse than that of other pleistocene animals to explain this situation, it would have to extend until almost the beginning of the ceramic epoch, which would not please the paleontologists.
Lithic Loltun also has not been been very amenable [to exploration]. There are very few well-defined techniques for dealing with stone fragments and cores; such techniques have varied widely from the beginning to the end. One of the reasons may derive from the uselessness of local flint for fine work. In the layers considered to be pre-ceramic there are very few tools: scrapers, shavers, knife-scrapers, jagged-edged tools (denticulados), and one sharp-ended tool (punta), all being of a very reduced size and totaling no more than 11 objects. Production techniques are limited to marginal finishing using stone chips and plates as the primary materials.
It may seem excessive the detail with which we have described the evidence that is so hard to understand about Loltun. But I believe that it is necessary because of the site's possible importance and because the findings have become widely known without specifying that the usable data until now are few and weak. Loltun has been incorporated into general theories about Mayan archeology and about the origins of humans in Mesoamerica.
Some authors limit themselves to mentioning an association between stone artifacts and Pleistocene animal bones, for others there is an association [p. 256] with Mammoth bones, and in a summary of the most relevant Mayan archeology in the last few years the long stratified sequence and the appearance of ceramics supposedly dated in 1800 BC is indicated. Regarding this last date, we must emphasize that among the first pots found in layer VII of "El Toro" there appear some fragments having characteristics of early pottery, but comparisons with material from Chiapas and from the Swazey complex in Belize have not given positive results, so the most probable date is Middle Preclassic.
The preceramic lithic material from Loltun has been tentatively assigned, because of it primitive and irregular character, to very early stages, before 14,000 BC. Others place it in the transition between the Pleistocene and Holocene and compare it with the complex of La Piedra del Coyote in the Guatemalan highlands and phase I of the Cave of Santa Martha in Chiapas. In this case it would have an age somewhere around 8000 to 10000 BC. It would be a manifestation of the Superior Cenolithic or until the Proto-Neolithic, or in other words, the Archaic.
In view of the evidence I have described, I lean toward the second possibility, and it is possible that its antiquity could be less, if we consider the continuity of the lithic of the Preclassic.
There is much left to do at Loltun. We are sure that there is an association of humans with pleistocene animals, but we must look in the part that has not yet been excavated for unmistakable evidence, where the strata have not been disturbed, where there is direct association of tools and bones, and direct action with the animals. We lack explicit traces of human visits to the cave as a home, places of work, or remains of other cultural elements besides only stone chips, and in the end, remains of prehistoric humans themselves.
I bolded the portions that were particularly relevant.
My impression, after reading more of the Hatt/Mercer texts, is that the soil levels in the Loltun cave were seriously disturbed which, along with the native difficulties of ascertaining timelines in cave excavations in general, have created a very confusing picture. I originally discounted the idea that burrowing animals could have been partly to blame for this confusing picture, but the Mercer text explicitly states that the impact of burrowing animals was evident, as Schmidt also speculates.
From page 118 of the Mercer text:
Layer 3, one foot eleven inches to two feet ten inches think, and capped with a solid white bed of pure ashes.
We soon found that Layer 3 had been much disturbed, and notably by the burrowing of animals.
It should be noted that the numbers of the layers vary depending upon researcher. Earlier, on page 116, Mercer defined “layer 3” as follows:
The bottom of Layer 3 marked, as before mentioned, the bottom line of human interference in the cave earth.
This seems to roughly correlate with Schmidt’s level VII.
Sorenson/Peterson also seem to indicate that Schmidt thought that the possibility of animals burrowing and disturbing layers and items within the layers “hard to accept”. But this is not what Schmidt stated might be hard to accept. From Schmidt:
Horse bones seem to have formed the last layer of the Pleistocene or Epi-Pleistocene in various caves, or they must have been dragged into the caves decades up to millenia later, something that is difficult to accept given the climatic conditions of the Tropics.
Schmidt and Mercer both clearly state that the actions of burrowing animals were plainly evident, not “hard to accept”.
The one conclusion that Schmidt, Mercer, and Hatt all agreed upon was that further study was needed. That further study was conducted and reported upon in the book I’ve already cited, Ice Age Faunas of North America. The following citations from that text draw clearer conclusions:
Henry C. Mercer (1896), who explored the cave and dug 2 pits in Chamber 3 in 1895, found similar ceramic and nonceramic layers. His attempt to locate preceramic artifacts with extinct fauna in association with Loltun or other nearby caves was unsuccessful. Some skeletal remains dubiously identified as Ursus (bear) were found in Loltun in a ceramic layer. Mercer reported the presence of Equus (horse) teeth and bones on the surface of three different caves. Although similar to the extinct horse Equus Occidentalis, the remains were identified as modern horse. Cope (1896) studied the remains of other animals collected by Mercer in Loltun, including species of opossums, bats, rabbit, mice, peccary, and deer if two sizes (page 263)
The most extensive study of the region was undertaken by Mr. and Mrs. Robert T. Hatt, who in 1929 and 1947 explored fourteen “cenotes” and dug in nine of them. (Hatt et al 1953). Two cenotes near Loltun contained the remains of extinct animals. Pleistocence Equus conversidens was recovered from Actun Lara. Actun Spukil produced a left tympanic ring and a molar fragment from the ground sloth, Paramylodon. In all, Hatt et al. (1953) collected forty-five species of mammals, of which six had been introduced by the Spaniards.
The Hatts collected only on the surface and in the top 10 cm of sediments in Chamber 3 in Loltun Cave (Hatt et al. 1953). Although further excavations were not pursued, the Hatts did recover twenty four mammal species, five of which were introduced (Mus Musculus, Canis familiaris, Equus axinus, Capra Hircus, and Bos Taurus). Native species represented two marsupials, one insectivore, four bats, one lagomorph, nine rodents, one carnivore, and one artiodactyls (Table 10.1). Hatt et al. (1953) indicated in their final report that the Loltun Cave was the most promising archaeological site for obtaining clues to the cultural and faunal changes since the end of the Pleistocene. (page 263)
A summary of the animal remains in the Loltun Cave was also provided.
The time range represented is from over 28,400 year BP. Not all taxa are found throughout this long period, but they can be divided into three main groups (Table 10.3). Group I (Holocene and Pleistocene) is formed by those species that occur through most of the stratigraphic sequence, accounting for more than half of the identified of the identified species (n = 39, 57.3 percent). Group 2 (n = 18 species, 26.5 percent) is composed of those species found only in the Holocene sediments. Species that occurred only in the Pleistocene strata constitute Group 3.
Table 10.3 Mammal Species from Loltun Cave Divided According to Their Temporal Record in the Excavation.
Group 1- Holocene and Pleistocene
Didelphis marsupialis, Marmosa canescens,M. Mexicana, Cryptotis, Cryptotis mayensis, Peropteryx macrotis, Pteronotus parnellii, Mormoops megalophylla, Chrotopterus auritus, Glossophaga soricina, Stumira lilium, Artibeus jamaicensis, hiroderma villosum, Desmodus rotundus, Diphylla ecaudata,Eptesicus furinalis, Lasiurus ega I. Intermedius, Nyctinomops laticaudatus, Herpailurus yagouaroundi, Leopardus pardalis, L. wiedii, Puma concolor, Panthera onca, Conepatus semistriatus, Spilogale putorius, Nasua narica, Mazama sp, Odocoileus virginiamus, Pecari tajacu, Sciurus deppei, S. yucatanemis, Orthogeomys hispidus, Heteromys gaumeri, Oryzomys couesi, Ototylomys phyllotis, Peromyscus leucopus, P. yucatanicus, Sigmodon hispidus, Sylvilagus floridanus.
Group 2 – Holocene Only
Philander opposum, Pteronotus davyi, Carollia brevicauda, Centurio senex, Natalus stramineus, Myotis keaysi, Eumops bonariensis, E. underwoodi, Promops centralis, Molossus rufus, Dasypus novemcinctus, Canis familiaris, Urocyon cinereoargenteus, Bassariscus sumichrasti, Procyon lotor, Mustela frenata, Coendou mexicanus, agouti paca
Group 3 – Pleistocene Only
Marmosa lorenzoi, desmodus cf. D draculae, Canis dirus, C. latrans, C. lupus, mephitis sp, Cuvieronius sp, Equus Conversidens, Bison sp, Hemiauchenia sp, Sylvilagus brasiliensis
page 267
Note that Equus Conversidens is listed as ONLY Pleistocene. The Bison reference is to a now extinct species that was extanct during the Pleistocene era. This is likely what Mercer originally thought were "cattle" bones.
Now, where were the Pleistocene animal remains found? The next citation makes it very clear:
The Pleistocene mammal fauna from Loltun Cave consist of those remains from the bottom of Level VII downward and is represented by fifty species (Groups 1 and 3) in forty genera, twenty-three families, and nine orders. This variety is one of the largest from the late Pleistocene of Mexico (Arroyo-Cabrales et al, in press; Kurten and Anderson 1981). Furthermore, it is the most diverse fossil mammal fauna for the Neotropical region of North and CentralAmerica (Fernasquia-Villafranca 1978; Webb and Perrigo 1984).
page 268
We thus see that the further study recommended by earlier researches soundly debunks the claims of apologists.