Prehistoric Sites of the Cagayan Valley Basin

Description

Paleolithic Sites of the Callao Limestone Formation: N17 42 11.74 E121 49 25.5
Paleolithic Sites of the Awidon Mesa Formation - Lanna, Andarayan, and Nangalisan:
Kalinga Archaeological Site: N17 33 45.0318 E121 33 35.7372
Lal-lo Neolithic Shell Midden Sites (Nagsabaran, Magapit, and Bangag, Lal-lo, Cagayan) and Gattaran Neolithic Shell Midden Sites (Gattaran, Cagayan): N18 12 05 E121 39 50

The Cagayan Valley Basin encompasses extensive and crucial archaeological sites in the Philippines. Research and excavations by the National Museum of the Philippines (NMP), and field research by the Cagayan Museum have yielded vast archeological findings including artifacts and traces of the past that date back to several periods: the Paleolithic Age, around 700,000 years ago when early humans navigated a different landscape; the Neolithic Age, a time when humans started to produce their own food through domestication of plants and animals; and Metal Age which covers the transition from 2000 Before Common Era (BCE) to 1000 Common Era (CE). Cagayan Valley, like many other provinces in the Philippines, was never isolated from foreign influence as was earlier believed. It was once a part of the long prehistoric international trade with neighboring countries from around the 10^th to 16^th century CE.

Paleolithic sites are located within the Cagayan Valley region which is bordered by the Sierra Madre Mountain range on the East; the Caraballo on the South; the Cordillera Central on the west; and the Babuyan Channel on the north. Found in two municipalities of the province, namely, Solana and Peñablanca, Paleolithic sites yielded the earliest stone tools and remains of extinct and extant species of animals.

Archaeological excavations undertaken on the western flank of the valley, particularly in Solana, Cagayan and Rizal, Kalinga resulted in the discovery of more than 68 Paleolithic sites within a distinct fossil-bearing deposits in Awidon Mesa formation. These sites yielded stone tools and fossils of extinct animals that include stegodons, elephants, rhinoceros, large tortoise, and wild pig. Previous reports by prominent paleontologists and archaeologists from Europe on the presence of Pleistocene megafauna fossils and chopper-chopping stone tools in the valley, was confirmed a decade ago with the discovery in Rizal, Kalinga of cutmark-bearing rhinoceros fossils with associated stone tools found in situ and directly dated at 709,000 years ago (Ingicco et al. 2018). Since the survey in the area in 2013 and yearly excavations at the site in Kalinga, evidence of early hominin occupation, lithic studies, and insights into faunal taxonomy and movements (Ingicco et al. 2016, Antoine et al. 2020) have been revealed, broadening and pushing back the frontiers of prehistory.

On the eastern flank of the valley in the Municipality of Peñablanca, archaeological exploration specifically in the Callao Limestone formation revealed the presence of 93 archaeological sites that yielded stone flake tools of Paleolithic industry and bones and shells of animals still living in the vicinities. Of these sites, 78 are caves and rock shelters. The earliest evidence of the lithic industry in Callao is dated around 28,980-27,420 cal. BP. The archaeological study of the caves in the Callao limestone formation also suggests the persistence of this Paleolithic technology until the post-Pleistocene period..  Furthermore, the discovery of human remains in the deep deposits of the cave was identified to be a new hominin species in the country called Homo luzonesis dating to at least 134,000 years ago. Morevoer, recent analysis of the charcoal pictograms drawn on the cave walls of the Callao formation revealed a 3500-year-old rock art heritage in the area (Jalandoni et al. 2021). In addition, three previously unknown extinct cloud rat species were also discovered to have inhabited cave sites in Peñablanca, adding to the biodiversity information of extinct endemic giant cloud rats in the past (Batomys cagayanensis, Carpomys dakal, Crateromys ballik) from when H. luzonensis was present up to the about 2000 years ago (Ochoa et al. 2021).

Vast estuarine shell midden sites are located along the banks of the Cagayan River in the Municipalities of Lal-lo and Gattaran, about 500 kilometers northeast of Manila. They first appear in preceramic layers approximately 7000 years ago during peak Holocene sea-level conditions associated with foragers who used chert and flake tools who subsisted on fauna such as wild pig, deer, rat, bird, riverine shellfish, fish and turtles and botanical sources such as tubers and nuts, probably including wild yam. By the Neolithic Period about 4200/4000 years ago, the preceramic shell middens reached approximately 100 x 50m in area and 3 m in depth. The Neolithic of the Cagayan Valley saw the introduction of various artifacts including red-slipped pottery, baked clay spindle whorls, polished stone adzes, bark-cloth beaters and body ornaments. Such ornaments include penannular ear pendants, bracelets and beads that were made of shell, baked clay, quartz schist and semi-precious stones including Taiwan nephrite (jade). The Neolithic of the Cagayan Valley also contains remains of domestic pigs and macrobotanical remains of rice (Oryza sativa) and Job’s tears (Coix lacryma-jobi). The macrobotanical evidence for rice is now established at three Neolithic sites of Nagsabaran, Magapit and Andarayan). The shell middens continued to be created by later groups through the Metal Age around 2400 years ago, where layers containing black-surfaced pottery occur and are associated with iron objects, bronze ornaments, and monochrome glass beads. Later settlers who exploited estuarine resources continued to expand the Cagayan Valley shell middens until recent times. The middens are made up of thick deposits of kabibe bivalve shells (Batissa childreni) with small quantities of gastropod and bivalve species including Thaira rudis, Thiara winteri, Melanoides tuberculata, Melanoides granifera, Melanoides maculata, Corbicula fluminea and Nitidotellina munuta. The biggest deposits of shells are found in Magapit and Bangag in Lal-lo and are more than 5m deep. The size and density intensity of the estuarine shell middens of the lower Cagayan Valley are unique in the Philippines. They encompass rich evidence for the settlement of the region beginning about 7000 years ago, through the Neolithic, Metal and more recent period (Hung et al. 2022). 

Justification of Outstanding Universal Value

The Cagayan Valley Basin encompasses extensive and crucial prehistoric archaeological significance which has a central role in the thriving existence of hominin species and their cultural traditions for the last 700 thousand years. It was proven habitable for humans and pre-modern hominins, providing them rich ecological niches where they can flourish and survive for millennia, as evidenced by at least three different hominin species. Within the property includes the butchered extinct rhinoceros and stone tools of an unidentified pre-modern hominin in Rizal, Kalinga dated at 709,000 years BP, fossilized skeletal remains of Homo luzonensis in Callao Cave dating as early as 134,000 years BP, and the varying cultural assemblages of Homo sapiens along the banks of Cagayan River and Callao limestone formations starting from around 29,000 years BP.

Criterion (v): The prehistoric sites of the Cagayan Valley Basin enrich our understanding not just the hominin diversity in the Philippines, but also the central role of the landscape in the thriving of these hominin species and their cultural traditions, in the span of over 700 thousand years. Archaeological evidence of at least three hominin species, including the butchered extinct rhinoceros and stone tools of an unidentified premodern hominin in Rizal, Kalinga at 709,000 years BP, fossilized skeletal remains of Homo luzonensis in Callao Cave dating as early as 134,000 years BP, and the varying cultural assemblages of Homo sapiens along the banks of Cagayan River and Callao limestone formations starting from around 29,000 years BP, demonstrated the merit of this wide landscape, which for millennia has gone through drastic transformations due to the geological uplifts and fluctuating sea levels. The Cagayan Valley Basin has proven habitable for humans and premodern hominins, providing them rich ecological niches where they can flourish and survive for millennia. The presence of megafauna in Kalinga and the evidence of their consumption using stone tools clearly shows how these premodern hominins utilized and exploited the available resources at that time for them to successfully thrive. The arboreal environment at the Callao limestone region in the eastern flank of the river basin would have allowed the evolution and emergence of Homo luzonensis as a different hominin species. Lastly, the vast riverine landscape at the middle of the valley basin provided a suitable home for the later arrival of various populations of Homo sapiens, who utilized the resources from its riverbanks, creating vast settlements and developing diverse cultural traditions.

The disappearance of premodern hominin populations at the Cagayan River Basin may have been attributed to the drastic ecological transformations brought by climate shifts and the expansion of the later Homo sapiens, as inferred from the archaeological and paleoenvironmental studies in the Philippines and Island Southeast Asia. While these hypotheses may serve as a lesson on the impact of environmental changes to the landscape, it also provides us insights on the risk of irreversible damage to the nominated property due the impact of irresponsible human intervention on the landscape.

Statements of authenticity and/or integrity

The archaeologists and experts from the National Museum of the Philippines, The School of Archaeology at the University of the Philippines and experts from partner research and academic institutions in several countries have been engaged in significant archaeological research in Cagayan Valley starting in the 1930s.  Their findings revealed the earliest trace of the emergence of humans in the Philippines, that was able to project back in time to the middle of the Pleistocene Epoch at 709,000 years ago (709 ± 68 ka). Archaeological work covering the Pleistocene period in northern Luzon, Philippines has been intensified and is now marked with growing precision and systematics. So far, explorations and excavations undertaken have provided evidence needed in the reconstruction of the chrono-stratigraphic framework of the fossil bearing deposits in the Philippines. Furthermore, re-excavations in the Pleistocene sites associated with stone tools of Paleolithic industry have been conducted to supplement to the current knowledge on the earliest evidence of hominin presence in the archipelago thus far.

The research on the shell midden sites of Lal-lo and Gattaran have resulted in the discovery of significant sites whose range is from the Paleolithic to Neolithic to the Age of Contact. In these areas, the discovery of 21 shell midden sites associated with earthenware, stone tools and bones provide the opportunity to apply an interdisciplinary approach involving several fields of endeavor to solve archaeological problems including paleo-environmental reconstructions.  Experts from Japan, Taiwan, Australia and the Philippines have gathered in the study area to discuss these archaeological problems and the most recent results of significant findings.

Comparison with other similar properties

Considerable data have been gathered on the distribution of extinct fauna and paleoenvironment in Southeast Asia, such as Sulawesi, Java, Timor and Flores and the Philippines (Aziz, 1988; Fox 1971; Glover 188; Hooijer 1948, 1975; Koenigswald 1958; Shutler 1988, Sondaar 1988; de Vos 1988, Bautista 1988). The discovery of earliest evidence of the presence of megafauna in the Philippines has widened the knowledge of distribution of these extinct animals in Southeast Asia. Through these findings, the reconstitution of the local faunal evolution and the position of the Philippines in relation to a large-scale migration pattern of vertebrates including humans in Southeast Asia are known.

To protect the area for the present and future generations of Filipinos, Presidential Decree No. 1109 was passed, "Declaring the Archaeological areas in the Cagayan Valley and Kalinga - Apayao Archaeological Reservation". The Kalinga Archaeological Site, The Callao Cave and the Lal-lo and Gattaran Shell Midden Sites have been declared by the NMP as National Cultural Treasure and Important Cultural Property as a means of further protecting these sites.

These sites are exceptional and crucial for the understanding of the emergence of humans and animals that would link the archipelago to the rest of Island Southeast Asia and Mainland Asia.