Abstract The tridactyl ichnotaxon Eubrontes giganteus commonly has been attributed to a carnivorous theropod dinosaur similar to Dilophosaurus or Liliensternus. For this to be correct, however, at least five unusual circumstances all must be true. (1) If the Eubrontes track-maker was a theropod, it created the most abundant large tracks found in the Connecticut Valley Hartford and Deerfield basins and yet, for unknown reasons, left no skeletal remains there at all. This pattern also holds true for the Kayenta Formation and Navajo Sandstone in the American Southwest. (2) The cursorial, bipedal, functionally tridactyl prosauropod Anchisaurus, which left two-thirds of the skeletal remains found in these same basins, for unknown reasons left no tracks there at all. (3) If the Eubrontes track-maker was a theropod, by happenstance, it was a theropod exactly the same size as Anchisaurus. (4) If the Eubrontes track-maker was a theropod, then published evidence for herding by Eubrontes track-makers must be due to local paleogeographic factors, not recognizable in the rock record, which created an illusion of herding. (5) The known stratigraphic range of Eubrontes tracks (Norian-Toarcian) by happenstance falls entirely within the known stratigraphic range of bipedal prosauropods (upper Carnian-Toarcian). None of these unusual circumstances need be true, however, if Anchisaurus was the Eubrontes track-maker. Recent reports of an anteriorly directed hallux in the Eubrontes track-maker provide compelling evidence that prosauropods, not theropods, made Eubrontes tracks. Parsimony strongly favors this conclusion and weighs heavily against the idea that the Eubrontes track-maker was a mysterious, elusive theropod whose skeletal remains have evaded discovery for nearly two centuries.

中文翻译：

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双足原蜥脚类恐龙可能是 Eubrontes Track-Makers 的证据

摘要 三趾鱼纲 Eubrontes giganteus 通常被认为是一种类似于双脊龙或 Liliensternus 的肉食兽脚亚目恐龙。然而，要使这一点正确，至少有五种不寻常的情况都必须是真实的。(1) 如果 Eubrontes 轨道制造者是兽脚类恐龙，它创造了在康涅狄格谷哈特福德和迪尔菲尔德盆地发现的最丰富的大型轨道，但由于未知原因，那里根本没有留下任何骨骼残骸。这种模式也适用于美国西南部的 Kayenta 组和 Navajo 砂岩。(2) 游走的、双足的、功能强大的三趾原蜥脚类近龙，在这些相同的盆地中留下了三分之二的骨骼遗骸，不知什么原因，在那里根本没有留下任何痕迹。(3) 如果 Eubrontes 的追踪者是兽脚亚目动物，那么偶然地，它是一种与近龙大小完全相同的兽脚类恐龙。(4) 如果Eubrontes的追踪者是兽脚亚目动物，那么Eubrontes的追踪者所发表的放牧证据一定是由于当地的古地理因素，在岩石记录中无法识别，从而造成了放牧的错觉。(5) 偶然发现的 Eubrontes 足迹 (Norian-Toarcian) 的已知地层范围完全属于双足原蜥脚类恐龙 (上 Carnian-Toarcian) 的已知地层范围。然而，如果 Anchisaurus 是 Eubrontes 的赛道制造者，那么这些不寻常的情况都不一定是真的。最近关于 Eubrontes 追踪器中前向拇趾的报道提供了令人信服的证据，证明原蜥脚类恐龙而非兽脚亚目制造了 Eubrontes 追踪。