Comparison of big theropod
Several giant length estimates have been proposed for different taxa, with varying degrees of accuracy. This diagram uses more rigorous estimates to avoid inaccuracy Sizes based on:
Spinosaurus     :
Ibrahim, Nizar; Sereno, Paul C.; Dal Sasso, Cristiano; Maganuco, Simone; Fabri, Matteo; Martill, David M.; Zouhri, Samir; Myhrvold, Nathan; Lurino, Dawid A. (2014). "Semiaquatic adaptations in a giant predatory dinosaur". Science. 345 (6204): 1613–6 "Semiaquatic adaptations in a giant predatory dinosaur"
Giganotosaurus     :
Hartman, S. (2013). "Mass estimates: North vs South redux"  Scott Hartman's Skeletal Drawing.com. Retrieved April 29, 2019.
Tyrannosaurus     :
"A T. rex Named Sue" (PDF)
Retrieved April 29, 2019
Mapusaurus      : the Theropod Database by Mickey Mortimer
Carcharodonotsaurus      :
Sereno, P. C.; Dutheil, D. B.; Iarochene, M.; Larsson, H. C. E.; Lyon, G. H.; Magwene, P. M.; Sidor, C. A.; Varricchio, D. J.; Wilson, J. A. (1996). "Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation". Science. 272 (5264): 986–991. doi:https://science.sciencemag.org/content/272/5264/986
Credits to:
Franoys (https://www.deviantart.com/franoys)
Slate Weasel (https://en.wikipedia.org/wiki/User:Slate_Weasel)
Scott A. Hartman - https://peerj.com/articles/6432/ (http://www.skeletaldrawing.com/)

Human silhouette from File:Silhouette of man standing and facing forward.svg.
Own work
KoprX