Skip to main content
SpringerLink
Log in

The Social Trackways Theory of the Evolution of Language

  • Thematic Issue Article: Symbols, Signals, and the Archaeological Record II
  • Published:
Biological Theory Aims and scope Submit manuscript

Abstract

The social trackways theory (for full introduction see my previous article on the topic in Biological Theory) is centered on the remarkable 3.66 mya Laetoli Fossilized Trackways, for they incontrovertibly reveal our ancestors were already obligate bipeds with very human-like feet, and were intentionally stepping in other band members’ footprints to maintain safe footing. Trackways are unique among natural sign systems in possessing a depictive narratively generative structure, somewhat like the symbolic sign systems of gestural languages. Therefore, due to daily embodied reiteration of their own and other band member’s old footprints, both for bipedal safety and as recognizable wayfinding markers for socio-ecological navigation, incrementally our Mid-Pliocene ancestors began to acquire a cognitive capacity for episodic personal memories and episodic future simulations. They began mentally representing themselves (and others) as intentional agents continuously travelling from the past into the future. This spatially and temporally self-projecting awareness manifested itself as extra theory of mind and mental space-and-time-travel capacities, which increasingly enabled intentional or conscious, top-down executive adjustment of past behaviors for the sake of achieving better ways of doing things in the future. Future-directed behavioral and cultural adaptations began to increase fitness in all domains, thus creating powerful selective feedback for further entrenchment. Here we focus on overtly or consciously intentional exploratory wayfinding and transmission of elsewhere-and-when information, using pragmatic, discursive modes of communication, which enabled far more cooperative and efficient foraging practices. Selection for better communication thus led to intentional trail marking and the earliest emergence of more conventional/symbolic depictive and gestural “protolanguages.”

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

Notes

  1. Alternatively, some theorists like Richard Moore (2016) claim no cognitive shift past the ape mind-set was needed, so an incipient gestural protolanguage (or another cultural shift like more complex toolmaking and/or foraging skill) does the selective triggering, backed by some environmental change. I am extremely skeptical, and only partly because the question of why no other great ape lineages (all of which make simple tools and can communicate with flexibly used gestures) attained language readiness remains unanswered by all these models. My other reasons are empirically based, and presented herein.

  2. I use this term deliberately, rather than just “mental time travel,” because it is of course perfectly possible to imagine one’s self in a different space in the here-and-now; for example, we do this continually when we are orienteering, as will be explained later in this paper.

  3. This autobiographical/narrative self-reflective awareness or consciousness was called “autonoesis” many years ago by Edmund Tulving, who more recently stated (2005) it was the key to all “higher” human cognitive capacities for creating cumulative culture. It is based on mental time travel, incorporating “nested scenarios” of who-what-where-when episodic memories and episodic future simulations or prospections in the “theatre of the mind” (Suddendorf and Corballis 2007).

  4. Canines were highly reduced in both sexes, but like their big flat molars with hyper-thick enamel, this was an adaptation allowing grinding motions of their powerful jaws when masticating tough sedge rhizomes.

  5. Recently reviewed evidence consisting of an australopithecine-type portion of jaw and molars discovered in East Africa in the 1970s has confirmed a date of 5.9–5.5 mya (Kissel and Hawks 2015), and large apes with similarly megadont characteristics were present in East Africa (Chororapithecus) around 10 mya and in Southeast Europe (Ouranopithecus/Graecopithecus) between 9.6 and 7.1 mya.

  6. Sahelanthropus tchadensis (7.2–6.8 mya); Orrorin tugensis (6.0–5.7 mya); Ardipithecus kadabba (6.4–5.5 mya); and Ardipithecus ramidus (4.4 mya): they were habitually bipedal, with progressively reducing canines and more sexually monomorphic body size, and possessed omnivorous Homo-like molars.

  7. Support for the “Waterside Ape” theory is now becoming a tidal wave of paradigmatic change, in the opinion of Sir David Attenborough (BBC Radio 4, September 2016, “The Waterside Ape”: two-part audio series).

  8. Large crocodiles would always be a worry in more extensive waterways, but they hunt mostly at night, and like all reptiles do not need to eat very often, compared to warm-blooded mammalian predators.

  9. In fact, Orrorin tugensis possessed the most human-like hominin thumb ever found.

  10. Recent work indicates bonobos are less derived than chimpanzees from the 8 mya Pan/Homo LCA (last common ancestor) (Diogo et al. 2017). This explains why they are more socially tolerant, and lends support to my alloparenting LCA theory.

  11. And their tails are much longer; those species that have remained less derived, more terrestrial omnivorous foragers in more open environments around upland watersheds (Tibetan and stump-tailed macaques) remain relatively tailless and have retained their alloparenting sociality.

  12. Towards the end of the rainy season hordes of catfish move onto seasonal floodplains to spawn; as the dry season commences they become trapped in small ponds and shrinking river-pools. Like salmon in Western North America, they provide essential saturated (Omega 3) fats and protein for all carnivores and omnivores.

  13. http://abcnews.go.com/blogs/entertainment/2013/08/bare-knuckle-babes-catch-catfish-with-bare-hands/.

  14. Their post-cranial elements also look very early, perhaps even earlier than habilis (Peter Hiscock, personal communication, June 2017).

  15. Many SET theorists have claimed they do not, thus maintaining their “afarensis was our direct ancestor” narrative.

  16. Extreme polar glaciation has often been triggered by massive volcanic events, and of course has much delayed but far more long-lasting climactic consequences.

  17. There are several ethnographic reports of trackers’ comments on how easy it is to recognize human bipedal trackways (e.g., Silberbauer 1981). Recently a few paces worth of footprints was found to be recognizable by computers to 99.8% accuracy, so the way we walk is as unique to us as our fingerprints (Pataky et al. 2012).

  18. It is important to remember here that stone-flake technology remained extremely simple for a million years after its first appearance, with the only difference being that in the beginning they were made using other stones as anvils, rather than through free-handed knapping. After Acheulian hand-axe technology kicked in around 1.7 mya, there was a further hiatus of a million years. It was more co-operative foraging, better reading of signs and routine behaviors of prey animals, more efficient communication, and increasing encephalization for neural storage of this knowledge that made erectus the most successful, eusocial predators on the planet.

  19. Here I use consciously rather than overtly because the orienteering cognitive process is usually introspective—of course when two or more people are travelling together, they may speak out loud, that is, their cooperative orienteering becomes overtly intentional, or ostensive.

  20. African locals still do this to attract catfish and eels within spearing range.

  21. There are many ethnographic examples of using highly informative whistled communication, and/or the use of mimetic bird calls, for coordinating individual activities during cooperative hunting excursions.

References

  • Alemseged Z, Spoor F, Kimbel WH et al (2006) A juvenile early hominin skeleton from Dikika, Ethiopia. Nature 443(7109):296–301

    Article  Google Scholar 

  • Andrews-Hanna JR (2012) The brain’s default network and its adaptive role in internal mentation. Neuroscientist 18(3):251–270

    Article  Google Scholar 

  • Attwell L, Kovarovic K, Kendal JR (2015) Fire in the Plio-Pleistocene: the functions of hominin fire use, and the mechanistic, developmental and evolutionary consequences. J Anthropol Sci 93:1–20

    Google Scholar 

  • Barboni D (2014) Vegetation of Northern Tanzania during the Plio-Pleistocene: a synthesis of the paleobotanical evidences from Laetoli, Olduvai, and Peninj hominin sites. Quatern Int 322–323:264–276

    Article  Google Scholar 

  • Bekoff M (2001) Observations of scent-marking and discriminating self from others by a domestic dog (Canis familiaris): tales of displaced yellow snow. Behav Process 55(2):75–79

    Article  Google Scholar 

  • Bennett MR, Reynolds SC, Morse SA, Budka M (2016) Laetoli’s lost tracks: 3D generated mean shape and missing footprints. Sci Rep 6:21916

    Article  Google Scholar 

  • Bobe R, Alemseged Z, Behrensmeyer AK (2007) Approaches to the analysis of faunal change during the East African Pliocene. In: Bobe R, Alemseged Z, Behrensmeyer AK (eds) Hominin environments in the East African Pliocene: an assessment of the faunal evidence. Springer, Berlin, pp 1–24

    Chapter  Google Scholar 

  • Boyd B (2017) The evolution of stories: from mimesis to language, from fact to fiction. Wiley Interdisciplinary Reviews: Cognitive Science, Hoboken

    Google Scholar 

  • Briana B (2014) Male Tibetan macaques′ (Macaca thibetana) choice of infant bridging partners. Zool Res 35(3):222

    Google Scholar 

  • Brumm A, Van Den Bergh GD, Storey M et al (2016) Age and context of the oldest known hominin fossils from Flores. Nature 534(7606):249–253

    Article  Google Scholar 

  • Burkart JM, Hrdy SB, Schaik CPV. (2009) Cooperative breeding and human cognitive evolution. Evolut Anthropol 18(5):175–186

    Article  Google Scholar 

  • Claessens L, Veldkamp A, Schoorl JM et al (2016) Large scale pantelleritic ash flow eruptions during the Late Miocene in central Kenya and evidence for significant environmental impact. Global Planet Change 145:30–41

    Article  Google Scholar 

  • Corballis MC (2014) The recursive mind: the origins of human language, thought, and civilization. Princeton University Press, Princeton

    Book  Google Scholar 

  • Corballis MC (2017) Language evolution: a changing perspective. Trends in Cognitive Sciences, Amsterdam

    Book  Google Scholar 

  • Crompton RH, Pataky TC, Savage R et al (2012) Human-like external function of the foot, and fully upright gait, confirmed in the 3.66 million year old Laetoli hominin footprints by topographic statistics, experimental footprint-formation and computer simulation. J R Soc Interface 9(69):707–719. http://doi.org/10.1098/rsif.2011.0258

    Article  Google Scholar 

  • Currie A, Sterelny K (2017) In defence of story-telling. Studies in History and Philosophy of Science Part A, Berlin

    Google Scholar 

  • de la Torre I (2016) The origins of the Acheulean: past and present perspectives on a major transition in human evolution. Phil Trans R Soc B 371(1698):20150245

    Article  Google Scholar 

  • Diogo R, Molnar JL, Wood B (2017) Bonobo anatomy reveals stasis and mosaicism in chimpanzee evolution, and supports bonobos as the most appropriate extant model for the common ancestor of chimpanzees and humans. Sci Rep 7(1):608

    Article  Google Scholar 

  • Ferretti F (2014) Travelling in time and space at the origins of language. Hum Mente J Philos Stud 27:243–268

    Google Scholar 

  • Ferretti F, Adornetti I, Chiera A et al (2017) Mental Time Travel and language evolution: a narrative account of the origins of human communication. Language Sciences, Amsterdam

    Google Scholar 

  • Gatty H (1998) Finding your way without map or compass. Courier Corporation, Dover Edition, Mineola

    Google Scholar 

  • Green DJ, Alemseged Z (2012) Australopithecus afarensis scapular ontogeny, function, and the role of climbing in human evolution. Science 338(6106):514–517. http://doi.org/10.1126/science.1227123

    Article  Google Scholar 

  • Haile-Selassie Y, Latimer BM, Alene M et al (2010) An early Australopithecus afarensis postcranium from Woranso-Mille, Ethiopia. Proc Natl Acad Sci 107(27):12121–12126. http://doi.org/10.1073/pnas.1004527107

    Article  Google Scholar 

  • Haile-Selassie Y, Latimer B, Lovejoy CO et al (2016) Conclusion: implications of KSD-VP-1/1 for early hominin paleobiology and insights into the chimpanzee/human last common ancestor. In: Haile-Selassie Y, Su DF (eds), The Postcranial Anatomy of Australopithecus afarensis. Springer, Netherlands, pp 179–187

    Chapter  Google Scholar 

  • Harmand S, Lewis JE, Feibel CS et al (2015) 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya. Nature 521(7552):310–315. http://doi.org/10.1038/nature14464

    Article  Google Scholar 

  • Hlubik S, Berna F, Feibel C, Braun D, Harris JW (2017) Researching the nature of fire at 1.5 mya on the site of FxJj20 AB, Koobi Fora, Kenya, using high-resolution spatial analysis and FTIR spectrometry. Curr Anthropol 58(S16):S000–S000

    Article  Google Scholar 

  • Hublin JJ, Ben-Ncer A, Bailey SE et al (2017) New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens. Nature 546(7657):289–292

    Article  Google Scholar 

  • Jeffares B (2014) Back to australopithecus: utilizing new theories of cognition to understand the Pliocene hominins. Biol Theory 9(1):4–15

    Article  Google Scholar 

  • Joordens JCA, Kuipers RS, Wanink JH, Muskiet FAJ (2014) A fish is not a fish: patterns in fatty acid composition of aquatic food may have had implications for hominin evolution. J Hum Evolut 77:107–116. http://doi.org/10.1016/j.jhevol.2014.04.004

    Article  Google Scholar 

  • Killin A (2016) Musicality and the evolution of mind, mimesis, and entrainment. Biol Philos 31(3):421–434

    Article  Google Scholar 

  • Kissel M, Hawks J (2015) What are the Lothagam and Tabarin Mandibles? PaleoAnthropology 37:43

    Google Scholar 

  • Kuhn SL, Raichlen DA, Clark AE (2016) What moves us? How mobility and movement are at the center of human evolution. Evolut Anthropol 25(3):86–97

    Article  Google Scholar 

  • Laden G, Wrangham R (2005) The rise of the hominids as an adaptive shift in fallback foods: plant underground storage organs (USOs) and australopith origins. J Human Evol 49(4):482–498

    Article  Google Scholar 

  • Leakey MD (1981) Discoveries at Laetoli in northern Tanzania. Proc Geologists’ Assoc, 92(2), 81–86. http://doi.org/10.1016/s0016-7878(81)80008-9

    Article  Google Scholar 

  • Leakey MD, Harris JM (1987) Laetoli, a Pliocene site in northern Tanzania. Clarendon Press. Oxford University Press, Oxford

    Google Scholar 

  • Leakey MG, Spoor F, Brown FH et al (2001) New hominin genus from eastern Africa shows diverse middle Pliocene lineages. Nature 410(6827):433–440. http://www.nature.com/nature/journal/v410/n6827/suppinfo/410433a0_S1.html

  • Leakey MG, Spoor F, Dean MC et al (2012) New fossils from Koobi Fora in Northern Kenya confirm taxonomic diversity in early Homo. Nature 488(7410):201–204. http://www.nature.com/nature/journal/v488/n7410/abs/nature11322.html#supplementary-information

  • Lee RB, DeVore I (eds) (1968) Problems in the study of hunters and gatherers. In: Man the Hunter. Aldine Publishing Company, Chicago, pp 3–12

  • Lieberman DE (2001) Another face in our family tree. Nature 410(6827):419–420

    Article  Google Scholar 

  • Lordkipanidze D, Vekua A, Ferring R et al (2005) Anthropology: the earliest toothless hominin skull. Nature 434(7034):717–718

    Article  Google Scholar 

  • Lovejoy CO, Simpson SW, White TD et al (2009a) Careful climbing in the Miocene: the forelimbs of Ardipithecus ramidus and humans are primitive. Science 326(5949):70, e71–e78. http://doi.org/10.1126/science.1175827

    Google Scholar 

  • Lovejoy CO, Suwa G, Simpson SW et al (2009b) The great divides: Ardipithecus ramidus reveals the postcrania of our last common ancestors with African apes. Science 73(5949):100–106. http://doi.org/10.1126/science.1175833

    Google Scholar 

  • Macho GA (2014) An ecological and behavioural approach to hominin evolution during the Pliocene. Quatern Sci Rev 96:23–31

    Article  Google Scholar 

  • Maestripieri D (1998) The evolution of male-infant interactions in the tribe Papionini (Primates: Cercopithecidae). Folia Primatol 69(5):247–251

    Article  Google Scholar 

  • McPherron SP, Alemseged Z, Marean et al (2010) Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia. Nature 466(7308):857–860

    Article  Google Scholar 

  • McPherron SP, Alemseged Z, Marean C et al (2011) Tool-marked bones from before the Oldowan change the paradigm. Proc Natl Acad Sci 108(21):E116. http://doi.org/10.1073/pnas.1101298108

    Article  Google Scholar 

  • Moore R (2016) Meaning and ostension in great ape gestural communication. Anim Cogn 19(1):223–231

    Article  Google Scholar 

  • O’Regan H, Turner A, Bishop L, Elton S, Lamb A (2011) Hominins without fellow travellers? First appearances and inferred dispersals of Afro-Eurasian large-mammals in the Plio-Pleistocene. Quatern Sci Rev 30(11):1343–1352

    Article  Google Scholar 

  • Organista E, Domínguez-Rodrigo M, Yravedra J et al (2017) Biotic and abiotic processes affecting the formation of BK Level 4c (Bed II, Olduvai Gorge) and their bearing on hominin behavior at the site. Palaeogeography, Palaeoclimatology, Palaeoecology, Amsterdam

    Google Scholar 

  • Osvath M, Gärdenfors P (2007) What are the evolutionary causes of mental time travel? Behav Brain Sci 30(03):329–330. http://doi.org/10.1017/S0140525X07002154 doi

    Article  Google Scholar 

  • Palombo MR (2013) What about causal mechanisms promoting early hominin dispersal in Eurasia? A research agenda for answering a hotly debated question. Quatern Int 295:13–27

    Article  Google Scholar 

  • Pataky TC, Mu T, Bosch K et al (2012) Gait recognition: highly unique dynamic plantar pressure patterns among 104 individuals. J R Soc Interface 9(69):790–800

    Article  Google Scholar 

  • Paul L (2017) First personal modes of presentation and the structure of empathy. Inquiry 60(3):189–207

    Article  Google Scholar 

  • Plummer T (2004) Flaked stones and old bones: biological and cultural evolution at the dawn of technology. Am J Phys Anthropol 125(S39):118–164

    Article  Google Scholar 

  • Price SA, Hopkins SSB, Smith KK, Roth VL (2012) Tempo of trophic evolution and its impact on mammalian diversification. Proc Natl Acad Sci USA 109(18):7008–7012. http://doi.org/10.1073/pnas.1117133109

    Article  Google Scholar 

  • Rolland J, Condamine FL, Beeravolu CR et al (2015) Dispersal is a major driver of the latitudinal diversity gradient of Carnivora. Global Ecol Biogeogr 24(9):1059–1071

    Article  Google Scholar 

  • Russon AE, Compost A, Kuncoro P, Ferisa A (2014) Orangutan fish eating, primate aquatic fauna eating, and their implications for the origins of ancestral hominin fish eating. J Human Evol 77:50–63

    Article  Google Scholar 

  • Sayers K, Lovejoy CO, Emery NJ et al (2008) The chimpanzee has no clothes: a critical examination of Pan troglodytes in models of human evolution. Curr Anthropol 49(1):87–114

    Google Scholar 

  • Sayers K, Raghanti MA, Lovejoy CO (2012) Human evolution and the chimpanzee referential doctrine. Annu Rev Anthropol 41:119–138

    Article  Google Scholar 

  • Scott-Phillips T (2014) Speaking our minds: why human communication is different, and how language evolved to make it special. Palgrave MacMillan, New York

    Google Scholar 

  • Shaw-Williams K (2011) The triggering track-ways theory. MA thesis, http://researcharchive.vuw.ac.nz

  • Shaw-Williams K (2014) The social trackways theory of the evolution of human cognition. Biol Theory 9(1):16–26

    Article  Google Scholar 

  • Shaw-Williams K (forthcoming) The social trackways theory of the evolution of human cognition, culture and communication. Dissertation, Australian National University

  • Silberbauer GB (1981) Hunter and habitat in the central Kalahari Desert. CUP Archive, Cambridge

  • Small MF (1990) Alloparental behaviour in Barbary macaques, Macaca sylvanus. Anim Behav 39(2):297–306. http://doi.org/10.1016/S0003-3472(05)80874-7

    Article  Google Scholar 

  • Sterelny K (2003) Thought in a hostile world: the evolution of human cognition. Blackwell Publishing, Malden

    Google Scholar 

  • Stewart KM (2014) Environmental change and hominin exploitation of C4-based resources in wetland/savanna mosaics. J Human Evol. http://doi.org/10.1016/j.jhevol.2014.10.003

    Google Scholar 

  • Suddendorf T (2013) The gap: the science of what separates us from other animals. Basic Books, New York

    Google Scholar 

  • Suddendorf T, Corballis MC (2007) The evolution of foresight: what is mental time travel, and is it unique to humans? Behav Brain Sci 30(3):299–313

    Google Scholar 

  • Sugiyama MS (2001) Food, foragers, and folklore: the role of narrative in human subsistence. Evolut Human Behav 22:221–240

    Article  Google Scholar 

  • Tomasello M (2009) Constructing a language. Harvard University Press, Cambridge

    Google Scholar 

  • Tomasello M (2014) A natural history of human thinking. Harvard University Press, Cambridge

    Book  Google Scholar 

  • Tudryn A, Abdessadok S, Gargani J et al (2016) Stratigraphy and paleoenvironment during the Late Pliocene at Masol paleonto-archeological site (Siwalik Range, NW India): preliminary results. CR Palevol 15(3):440–452

    Article  Google Scholar 

  • ​Tulving E (2005) Episodic memory and autonoesis: uniquely human? In: Terrace HS, Metcalfe J (eds) The missing link in cognition: origins of self-reflective consciousness. Oxford University Press

  • Van Den Bergh GD, Kaifu Y, Kurniawan I et al (2016) Homo floresiensis-like fossils from the early Middle Pleistocene of Flores. Nature 534(7606):245–248

    Article  Google Scholar 

  • Villmoare B, Kimbel WH, Seyoum C et al (2015) Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia. Science 347(6228):1352–1355

    Article  Google Scholar 

  • White TD, Lovejoy CO et al (2015) Neither chimpanzee nor human, Ardipithecus reveals the surprising ancestry of both. Proc Natl Acad Sci 112(16):4877–4884. http://doi.org/10.1073/pnas.1403659111

    Article  Google Scholar 

  • WoldeGabriel G, Heiken G, White TD et al (2000) Volcanism, tectonism, sedimentation, and the paleoanthropological record in the Ethiopian Rift System. Geological Society of America, Boulder, pp 83–99

    Google Scholar 

  • WoldeGabriel G, Ambrose SH, Barboni D (2009) The geological, isotopic, botanical, invertebrate, and lower vertebrate surroundings of Ardipithecus ramidus. Science 65(5949):65e61-65e65. http://doi.org/10.1126/science.1175817

    Google Scholar 

  • Wrangham R, Cheney D, Seyfarth R, Sarmiento E (2009) Shallow-water habitats as sources of fallback foods for hominins. Am J Phys Anthropol 140(4):630–642. http://doi.org/10.1002/ajpa.21122

    Article  Google Scholar 

Download references

Acknowledgements

Earlier drafts of this article were written while I was fully supported by a PhD Research Scholarship from the Australian National University. Many thanks to my present and earlier supervisors Kim Sterelny, Peter Hiscock, Ben Jeffares, Brett Calcott, and Russell Gray; my past and present fellow students, especially Adrian Currie and Anton Killin; my walking/sounding-board friend Antek Skotnicki, and my computer-guru friend John Mills in Lyneham, Canberra; my oldest/longest-suffering nonacademic friends—and, of course, my family—for, let’s face it, their extreme patience, combined with discerning yet always encouraging critiques and/or pragmatic/emotional support. I am also very grateful to friends Ben Frazer and Kirsty Douglas for harboring my old camper van on their property whenever I am not using it as temporary accommodation in Canberra.

Author information

Authors and Affiliations

  1. Research School of Social Sciences, School of Philosophy, Australian National University, Canberra, ACT, Australia

    Kim Shaw-Williams

Authors
  1. Kim Shaw-Williams
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kim Shaw-Williams.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shaw-Williams, K. The Social Trackways Theory of the Evolution of Language. Biol Theory 12, 195–210 (2017). https://doi.org/10.1007/s13752-017-0278-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13752-017-0278-2

Keywords

Search

Navigation