Question: In which year did Tom Gray aid in the discovery of a hominid fossil

Context paragraphs:
Post-orbital constriction: In physical anthropology, post-orbital constriction is a narrowing of the cranium (skull) just behind the eye sockets (the orbits, hence the name), in primates — including primitive hominids.  This constriction is very noticeable in non-human primates, slightly less so in Australopithecines, even less in Homo erectus and the most primitive Homo sapiens.  It completely disappears in modern Homo sapiens.  Thus, it is a useful, quantifiable measure of how far along the evolutionary path a hominid fossil might be placed.

Michel Brunet (paleontologist): Michel Brunet (born on April 6, 1940) is a French paleontologist and a professor at the Collège de France.  In 2001 Brunet announced the discovery in Central Africa of the skull and jaw remains of a late Miocene hominid nicknamed Toumaï.  These remains are believed to predate the earliest previously known hominid remains, Lucy, by over three million years.

Early hominids in Southeast Asia: The theory of out of Africa has predominated an entire floor of human evolution discussion for many decades.  This is despite that fact that many evidences found in other parts of the world seem to suggest other thoughts and theories on how our ancestors might have migrated or ‘evolved’ outside Africa.  Yet the recent aDNA and fossils evidence prove those possibilities are impossible or in questions The region of Southeast Asia is considered a possible place for the evidence of early hominid remains that could be found due to the pathway between Australia and mainland Southeast Asia that early hominid migration could occur.  One of many evidences is of the early hominid found in central Java of Indonesia in the late 1800s by Eugene Dubois, and later in 1937 at Sangiran site by G.H.R. van Koenigswald.  These skull and fossil materials are Homo Erectus or Dubois named "Pithecanthropus erectus," and "Meganthropus palaeojavanicus" by van Koenigswald.  They were dated back to c. 1.88 and 1.66 Ma suggested by Swisher et al. from volcanic rocks dating method

WLH-50: Fossil WLH-50 is a partial cranium fossil that was discovered in 1982, in the Willandra Lakes Region of Australia and was reconstructed by Alan Thorne.  Speculation surrounds the exact age of this fossil hominid and a debate concerning its ancestry in relation to other late Pleistocene hominids, as well as, Ngandong hominids due to their close resemblance to one another.

Gen Suwa: Gen Suwa (born 1954) is a Japanese paleoanthropologist.  He is known for his contributions to the understanding of the evolution of early hominids, including the discovery of a tooth from a hominid that was more than one million years older than the oldest previously known hominid.  The discovery changed scientific opinion regarding the ancestral splits between humans, chimps and gorillas.

Lucy (Australopithecus): Lucy is the common name of AL 288-1, several hundred pieces of bone fossils representing 40 percent of the skeleton of a female of the hominin species "Australopithecus afarensis".  In Ethiopia, the assembly is also known as Dinkinesh, which means "you are marvelous" in the Amharic language.  Lucy was discovered in 1974 in Africa, near the village Hadar in the Awash Valley of the Afar Triangle in Ethiopia, by paleoanthropologist Donald Johanson of the Cleveland Museum of Natural History.

Garniss Curtis: Garniss H. Curtis, (born May 27, 1919 – died December 19, 2012) was a professor emeritus of geology at the University of California, Berkeley, geochronologist, volcanologist, geophysicist, and founder of the Berkeley Geochronology Center.  In 1960, Curtis and fellow UC Berkeley geophysicist Jack Evernden used potassium-argon dating methods developed by UC Berkeley physicist John Reynolds on minerals found in tephra deposits collected by Evernden to date Mary Leakey's 1959 Olduvai Gorge Bed I hominin "Zinjanthropus" ("Paranthropus boisei") to 1.89 to 1.57 Mya.  The great age of the fossil hominid and associated stone tools in the bed pushed back the then accepted age of the Pleistocene another million years, causing a stir in the geology community.  The dating of these fossil finds is considered a starting point for the collaboration of paleoanthropology and geochronology.

Phillip V. Tobias: Phillip Vallentine Tobias FRS (14 October 1925 – 7 June 2012) was a South African palaeoanthropologist and Professor Emeritus at the University of the Witwatersrand in Johannesburg.  He was best known for his work at South Africa's hominid fossil sites.  He was also an activist for the eradication of apartheid and gave numerous anti-apartheid speeches at protest rallies and also to academic audiences.

Tom Gray (archaeologist): Tom Gray is an archaeologist that aided in the discovery of the hominid fossil Lucy, alongside Donald Johanson.  During their expedition, Gray, then a graduate student, prompted Johanson to return to a previously explored dig site where Johanson then discovered the fossilized remains of Lucy.

Andre Keyser: Andre Werner Keyser (8 March 1938, Pretoria – 15 August 2010, Pretoria), was a South African palaeontologist and geologist noted for his discovery of the Drimolen hominid site and of numerous hominid remains.

Supporting paragraphs: Tom Gray (archaeologist) Lucy (Australopithecus)
Answer: 1974