A collection of etched limestone pebbles found by the banks of Kishon River in northern Israel’s Jezreel Valley may bear markings used to record the passage of seasons that predate the invention of writing by 20,000 years.

One of the carved stones unearthed at the site, marked with the head of a bird, may be among the oldest ritual objects ever found in the Holy Land. (A 30,000-year-old horse incised on a limestone plaque found in the Hayonim Cave in the Galilee predates the Ein Qashish finds and is among the oldest representations of the beast.)

The etchings were made between 23,000 and 16,500 years ago on limestone pebbles that fit comfortably in the palm of your hand. They are “rare evidence of graphic symbols applied by late Pleistocene hunters-gatherers in the Levant,” the authors of a study published August 24 in the online journal PLoS ONE said, and they’re indicative of social complexity among the inhabitants of the site.

The three stone carvings were discovered in 2012-2013 during excavations conducted at Ein Qashish by the Israel Antiquities Authority as part of the expansion of Highway 70 in northern Israel’s Jezreel Valley, just north of the modern city of Yokne’am.

Radiocarbon dating of charcoal fragments found in the same layer as the stones dated some to around 23,000 years ago and others to 17,000-15,000 years ago. Other small stone tools from the layer point helped pinpoint the date of the bird’s-head plaquette (small low-relief sculpture) to the latter period, the Epipalaeolithic — the epoch just before the dawn of agriculture.

One stone is marked with a hatchmarked design, referred to by researchers as the ladder plaquette. Another has a series of chevrons and geometric shapes. The most striking, however, bears the unmistakable head of a bird, identified by ornithologists as that of a bald ibis.

Illustrative photo of a bald ibis. (CC BY-SA Tony Hisgett, Flickr)

Illustrative photo of a bald ibis. (CC BY-SA Tony Hisgett, Flickr)

This stone, the authors of the paper wrote, is marked on one side by “the head of a bird seen in profile, together with a slightly curved, deeply incised line right above it. The bird is characterized by a large, curved beak and three ‘feathers’ in the form of little curvilinear, roughly parallel lines attached to the bird’s nape. A large round eye appears in the middle of the upturned, drop-shaped head.”

Historically, the bald ibis was found across Central Europe, North Africa and the Middle East, but destruction of habitat and hunting decimated its numbers. Today the bald ibis is a critically endangered species, with most of the remaining population surviving in Morocco.

The backside of the plaquette resembles the design on one of the other stones, featuring several deep lines forming “a motif composed of several deeply incised chevron-like signs, two of them forming a rhombus divided into two triangles in the middle of the composition.”

Citing the use of bird imagery in other prehistoric art, including the enigmatic “Bird Man” from the Lascaux Cave in southern France, the authors speculate that the bird engraving may have “a spirit-related interpretation… especially considering the context of the find.”

Ein Qashish’s location near the Kishon River in the Jezreel Valley made it an ideal base camp for hunter-gatherer communities over the eons. Archaeologists posit that the presence of communal inhabitation at the site over the ages “implies regulating social issues related to reproduction, sharing resources and enhancing and/or renewing alliances — activities which are likely to be accompanied by rituals.”

“Thus, the interpretation of the bird plaquette as an object employed in ritual, or depicting ritual-related accessories, as well as interpretation in terms of some cosmological belief/perception or an emblem of a particular group of hunters are all viable,” the article said.

A 16,500-year-old limestone palette engraved with a bird's head found at Ein Qashish in northern Israel. ( CC BY, PLoS ONE; A Unique Assemblage of Engraved Plaquettes from Ein Qashish South, Jezreel Valley, Israel: Figurative and Non-Figurative Symbols of Late Pleistocene Hunters-Gatherers in the Levant)

A 16,500-year-old limestone palette engraved with a bird’s head found at Ein Qashish in northern Israel. ( CC BY, PLoS ONE; A Unique Assemblage of Engraved Plaquettes from Ein Qashish South, Jezreel Valley, Israel: Figurative and Non-Figurative Symbols of Late Pleistocene Hunters-Gatherers in the Levant)

Alla Yeroshevich, an Israel Antiquities Authority archaeologist who was lead author of the study, hedged her bets when describing the plaquette as a ritual object because it’s “[too] small to interpret it as a device displayed in public ritual with certainty.”

When nomadic groups gathered at Ein Qashish in antiquity, she said, “a variety of issues [had] to be solved, among them mating/marriage, alliances, exchange of information etc. Each of these activities indeed could have been accompanied by rituals.

“If we assume that it happened during autumn or spring when the bald ibis was observed in the sky, the rituals could have been connected to this bird,” she said. “It is very possible that the aggregating groups had their own emblem to be identified with during the aggregation events.” One group may have chosen the ibis as its standard.

The authors of the article also posited that the ibis could have been used as “a cue to some seasonal change” linked to the bird’s migratory patterns. The marks on the back of the stone could have been symbols corresponding to spring or autumn, when the bald ibis transited the Levant.

The ladder plaquette, the authors said, may have served as a rudimentary “artificial memory system” which could have kept track of “time and location for particular activities, events of aggregation, either for specialized hunting, marital issues, rituals, exchange of resources.”

The people who created the objects were members of a society on the cusp of the agricultural revolution, transitioning from a peregrinating to a sedentary lifestyle. Compared to contemporary human populations in Europe, where the need to track shifting seasons for survival was more imperative, there was less environmental pressure in the less seasonal Levant to do so.

Nonetheless, the authors said, the etchings may have served as “records or notations related to availability of resources and timing of aggregation events” — in layman’s terms: a primitive calendar.

“This is use of symbols which others can understand,” Yaroshevich said. “It’s like you writing [the numeral] 1 and that’s something that everyone in the world understands its significance.”

The rarity of these sorts of objects in the historical record in the Levant may derive from a lesser necessity for such technology to survive in a region with less drastic seasonal shifts, Yaroshevich said.

At the same time, “it could be that they used graphics but with degradable media — wood, ochre — so we don’t find it,” she told The Times of Israel in a telephone interview.

The fact that symbols similar to the ones found at Ein Qashish have been discovered at contemporary prehistoric sites Europe and East Asia, she added, point to there being an “older source” in Africa.