Dreadnoughtus: Why are new taxa named using Dog Latin?
There is an International Commission on Zoological Nomenclature, to which submissions for new organisms' names is strongly recomended. The discoverer does have some leeway within this system if there is no Latin name that well-describes this species. Your example is one of many.
Chapter 31, for example, clearly states:

31.1.1. A species-group name, if a noun in the genitive case formed from a personal name that is Latin, or from a modern personal name that is or has been latinized, is to be formed in accordance with the rules of Latin grammar.

Examples. Margaret, if latinized to Margarita or Margaretha, gives the genitives margaritae or margarethae; similarly Nicolaus Poda, even though the name of a man, if accepted as a Latin name, gives podae; Victor and Hercules, if accepted as Latin names, give victoris and herculis; the name of Plinius, a Roman, even though anglicized to Pliny, gives plinii; Fabricius and Sartorius, if treated as Latin names, give fabricii and sartorii, but if treated as modern names give fabriciusi and sartoriusi; Cuvier, if latinized to Cuvierius, gives cuvierii.

31.1.2. A species-group name, if a noun in the genitive case (see Article 11.9.1.3) formed directly from a modern personal name, is to be formed by adding to the stem of that name -i if the personal name is that of a man, -orum if of men or of man (men) and woman (women) together, -ae if of a woman, and -arum if of women; the stem of such a name is determined by the action of the original author when forming the genitive.

Example. Under this provision, the species-group names podai from Poda, victori from Victor, and cuvieri from Cuvier are admissible. The names puckridgei and puckridgi may be formed from Puckridge.


Similar rules apply for genus and family names.
Since your example was a new genus and species, it didn't &quot;fit&quot; into previous categories (in the future, if and when similar discoveries are made that shed light on the genus' relation to others, the name can and will be changed accordingly, with or without the authors' approval).

According to the research team that discovered the taxon, the genus name Dreadnoughtus &quot;alludes to the gigantic body size of the (which presumably rendered healthy adult individuals nearly impervious to attack)&quot; and to the two dreadnought battleships of the Argentine Navy, the ARA Rivadavia and ARA Moreno. Thus, the genus name also honors the country (Argentina) in which Dreadnoughtus schrani was discovered. The name of the type species, schrani, was given in recognition of the American entrepreneur Adam Schran for his financial support of the project. - Wikipedia

A &quot;good&quot; or &quot;useful&quot; taxon is commonly taken to be one that reflects evolutionary relationships. Since this one does not, in a few decades, this name may well be gone.