Tomas Marco Nadal is the author of 'Kalar', a prehistoric series published in small books. He signed his work with Tomas Marco, T. Marco or just simply Marco. His father was killed when Nadal was aged 7, because of his religious beliefs. Therefore, he had to start working at a young age to support his family. He stopped his studies and took on several jobs, but always remained eager to learn. He showed big interest in history and archeology, but also in art and drawing. He learned the finer points of the comics profession of Jesus Blasco and Vicente Roso.
After several years of refusals, Marco Nadal was finally assigned by Marco publishers to illustrate 'El Mago del Lago' for their fairytale collection. For the next couple of years, Tomas Marco Nadal worked for several publishers, illustrating for several collections. In the early 1960s, he drew for several humorous magazines of Bruguera, like DDT, Tio Vio and Din Dan. He also illustrated some 'Capitan Trueno' stories. In 1963, Nadal started to work for the French market with 'SOS Titan' for Super Boy magazine, and his most famous creation, 'Kalar'. This series appeared from 1963 to 1983 (from 1969 also in his native Spain) and showed Nadal's interest in the history through the beautiful paintings of the animals of the jungle and the prehistoric monsters.