Question: Marina Petrella  is a former member of the Red Brigades that operated during which an era known as what ?

Context paragraphs:
Mario Moretti: Mario Moretti (born 16 January 1946) is an Italian terrorist.  A leading member of the Red Brigades in the late 1970s, he was one of the kidnappers of Aldo Moro, president of Italy's largest party, Democrazia Cristiana, and several times premier, in 1978; he later confessed to killing the politician.

Renato Curcio: Renato Curcio (] ; born 23 September 1941) is the former leader of the Italian left-wing militant organization, the Red Brigades ("Brigate Rosse").

Alberto Franceschini: Alberto Franceschini (born 26 October 1947) is an Italian former terrorist, a founder and leading member of the Italian left-wing militant organization, the Red Brigades ("Brigate Rosse"), along with Renato Curcio, Margherita Cagol and Mario Moretti.

Adriana Faranda: Adriana Faranda (born 7 August 1950) is an Italian former terrorist, who was a member of the Red Brigades during the kidnapping of Aldo Moro.

Alessio Casimirri: Alessio Casimirri (born 1951) is an Italian terrorist and member of the Red Brigades (BR), currently fugitive.

Red Brigades: The Red Brigades (Italian: "Brigate Rosse" ] , often abbreviated "BR") was a left-wing paramilitary organization, based in Italy, responsible for numerous violent incidents, including assassinations, kidnapping and robberies during the so-called "Years of Lead".

Marina Petrella: Marina Petrella (born 23 August 1954) is a former member of the terrorist Italian left wing group the Red Brigades.

Valerio Morucci: Valerio Morucci (born 22 March 1949) is an Italian former terrorist, who was a member of the Red Brigades and who took part in the kidnapping and assassination of Aldo Moro in 1978.

Prospero Gallinari: Prospero Gallinari (1 January 1951 – 14 January 2013), also known as "Gallo" (i.e. "rooster"), was an Italian terrorist, a member of the Red Brigades (BR) in the 1970s and 1980s.

Suqour al-Sham Brigades: The Suqour al-Sham Brigades (Arabic: ألوية صقور الشام‎ ‎ , English: Hawks of the Levant Brigades ), also known as the Sham Falcons Brigades, was an armed rebel organisation formed by Ahmed Abu Issa early in the Syrian Civil War to fight against the Syrian Government.  It was a member of the Islamic Front and a former unit of the Free Syrian Army and the Syrian Islamic Liberation Front.  They have a history of coordinating with Ahrar al-Sham and al-Qaeda's al-Nusra Front (a group rebranded as Tahrir al-Sham since January 2017), though clashes with the latter broke out in January 2017.  In March 2015, the Suqour al-Sham Brigades merged with Ahrar ash-Sham, but left Ahrar al-Sham in September 2016.  Also, in September 2016, they joined the Army of Conquest which Ahrar al-Sham is also a member.  On 25 January 2017, Suqour al-Sham rejoined Ahrar al-Sham, but later regained some autonomy as an ally of Ahrar al-Sham.

Supporting paragraphs: Marina Petrella Red Brigades
Answer: Years of Lead